ELSEVIER Nuclear Physics A 645 (1999) 331-375
N U C L E A R P H Y S I C S A
Nuclear structure studies of 125Te with (n,y), (d,p) and (3He,ce) reactions
J. Honzfitko a, I. Tomandl a,l, W. Bondarenko b'e'2, D. Bucurescu c, T. von Egidy b, j. Ott d, W. Schauer b, H.-E Wirth b, C. Doll h, A. Gollwitzer d, G. Graw d, R. Hertenberger d, B. D. Valnion o
a Nuclear Physics Institute, 250 68 l~e~, Czech Republic b Physik-Department, Technische Universittit Miinchen, D-85748 Garching, Germany
c Institute of Atomic Physics, Bucharest, Romania d Sektion Physik, Universitd't Miinchen, D-85748 Garching, Germany
e Nuclear Research Center, Latvian Academy of Sciences, LV 2169 Salaspils, Latvia
Received 23 July 1998; revised 14 October 1998; accepted 26 October 1998
Abstract
Levels in ~25Te were investigated in the range up to 3.3 MeV excitation energy by the (n,y), (d,p) and (3He,a) reactions. Over 160 levels and about 360 y-transitions were established, most for the first time. The states below 2.3 MeV with the most complete spectroscopic information were interpreted in terms of the interacting boson-fermion model (IBFM). Unitary treatment of both positive- and negative-parity states is achieved with the same model parameter close to the intermediate case between 0 ( 6 ) and U(5) limits. Excitation energies, electromagnetic transition rates, y-branchings and spectroscopic factors are discussed in connection with the possible structures. A family of low-spin negative-parity states has been identified and understood by the IBFM proving their antialigned origin. (~ 1999 Elsevier Science B.V.
PACS: 21.10.-k; 23.20.Lv; 27.60.+j Keywords: Nuclear reactions: 124Te(n,y), E = thermal, measured E~, I v, ),),-coin.; Binding energy; :24Te(d,p), E = 17 MeV; 126Te(3He,a), E = 32 MeV; Measured particle spectra; Enricbed targets; Ge detectors; Magnetic spectrograph; 125Te deduced levels; J, ~', ),-Branching ratios; Spectroscopic factors; Interacting boson-fermion model calculation and comparison
t Corresponding author. E-mail: [email protected] 2 Permanent address: Nuclear Research Center, LV 2169 Salaspils, Latvia.
0375-9474/99/$- see front matter (~) 1999 Elsevier Science B.V. All rights reserved. PII S0375-9474(98) 00588-0
332 J. Honz6tko et al./Nuclear Physics A 645 (1999) 331-375
I. Introduction
Te nuclei with only two protons beyond the closed shell Z = 50 span the wide neutron number region N = 50-82 (A = 112-134) allowing the investigation of the evolution of the main nuclear structures when the number of valence neutrons is gradually changed.
In general, the level schemes of odd-mass tellurium nuclei are expected to result
from the lg7/2, 2d5/2, 2d3/2, 3sl/2 and unique-parity lh11/2 neutron orbits coupled to the even-even core states [ 1-3]. This type of coupling accounts for the low-lying positive- parity states in 125Te [4] as well as many high-spin states [5]. At higher excitation energies the single neutron states are strongly fragmented in a wide energy region. The systematics of their population in nucleon transfer reactions were studied in detail in Refs. [ 6-9] . One puzzling result from these experiments is the anomalous asymmetrical population of the lh1~/2 neutron orbit observed in the stripping and pick-up process.
The negative-parity states are of particular interest. The systematic appearance of low-lying intruder states j - 1, j - 2, etc. arising from the hn~/2 orbit was previously explained by Kuriyama et al. [ 10] using so-called dressed three- and more-quasiparticle modes. On the other hand, in accordance with the systematic finding in a wide region
Z = 44-57, the aligned coupling scheme of the hi 1/2 orbit is one of the most fundamental excitation modes in nuclei across the Z = 50 shell closure. In going from Sn (Z = 50) to Ba (Z = 56) nuclei the general character of negative-parity yrast states is changed from A J = 2 to A J = 1 structures due to different aspects such as position of chemical potentials, sign of the product qQ, blocking effect, shape dynamical polarization, etc. Experience [ 11 ] shows that the sequence of favored high-spin states is not particularly sensitive to model assumptions. In this respect the position of the low-spin negative- parity states could be more sensitive to details of particle core coupling. In a simple picture suggested in Refs. [ 12,13] the appearance of low-spin states of the same lhll/2 family occurs under small quadrupole deformation. In the context of the model these states could be interpreted as antialigned members (with antiparallel angular momenta of the odd particle and the core). Experimentally, such states have been identified in Pd nuclei [12,14], 113Cd [15] and 135Ba [16]. The alternative description of these structures by the interacting boson-fermion model [ 17], the pairing-plus-recoil rotor model [ 18], and the triaxial rotor model [ 19] is as good as or even better than by the simple models of Refs. [ 12,13].
Deeper understanding of the various aspects mentioned above needs extensive and complete experimental information. As a continuation of our systematic studies of Te isotopes [20-23] we present here experimental data obtained with the different and complementary reactions (n,y), (d,p) and (3He,or). In the present work the interact- ing boson-fermion model (IBFM) has been applied extensively for the description of both negative- and positive-parity states. Some results of this complex work have been reported separately [24-26].
J. Honz6tko et al./Nuclear Physics A 645 (1999) 331-375
2. Experimental procedures
333
2.1. Thermal neutron capture studies
2.1.1. Single y-ray measurements
Single y-ray spectra and yy-coincidences following thermal neutron capture in 124Te were measured with semiconductor detectors at the light-water reactor LWR-15 at l~e~. The target consisted of 1.2 g of metallic Te enriched in 124Te to 92.4%. It was irradiated by thermal neutrons from a neutron guide [27]. Single y-ray spectra were recorded
with a 22% HPGe detector with a resolution of 2.0 keV at the 1332 keV 6°Co line and 4.8 keV at 6533 keV. For calibration purposes an auxiliary measurement was performed
with a mixed Te-CI target. The energy calibration was carried out with the well-known low-energy transitions in 125Te [41], y-rays from the 35Cl(n,y) reaction [28] and
prominent background lines of 2H and 6°Co. The intensities of y transitions in 125Te
were normalized using the absolute intensity of 7.8% of the 6620 keV line in 36C1 [28]. The systematic error of 20% in the determination of absolute intensities in 125Te is
associated with the uncertainty of the capture cross section of 12aTe [29]. In order to identify the y-rays belonging to the 123Te(n,y) reaction a separate run was performed
with a natural tellurium target. All y-rays assigned to 125Te with a possible placement
in the level scheme are listed in Table ! of Ref. [40].
2.1.2. yy-coincidence measurements
The yy-coincidence measurements were undertaken with a 22% HPGe and a 12% Ge(Li) detector. The present measurements were performed with higher statistics and
number of coincidence gates than in our previous study [24]. For a period of 21 days,
altogether 4 × 108 coincidences were accumulated and stored in an event-by-event format.
Coincidence spectra were obtained off-line by setting gates on 29 primary transitions and 34 secondary transitions. An example of such a spectrum is given in Fig. 1. Further details of the experimental setup and acquisition system are given elsewhere [27]. The
results of the yy-coincidence measurements are given in Table 1.
2.2. Light ion induced reactions
The nucleon transfer reactions with light ions are an important complementary tool to the (n,y) reaction for studying the properties of nuclear states. The experiments were performed at the Tandem Accelerator of the University and Technical University of Munich. The reaction products were analyzed in the Q3D spectrograph [30] equipped with a position sensitive cathode strip detector with a single strip readout [31,32] and a long focal plane detector with trace reconstruction [ 33]. The type of incident particle in a gas-filled detector chamber can be identified by sorting the energy loss signal from the anode wires versus the energy rest signal produced by the plastic scintillator.
334 J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
Table 1 Results from ),y-coincidence measurements
Gated y-ray y-Rays observed in coincidence (keV) (keY)
176 a
204 a 380
408
428
444
463 b
502
529 538
547
574 590 ¢
204,248, 285, 321,466, 518, 533, 536, 547, 557, 628, 702, 751, 786, 794, 797, 889, 913, (924), 938, 1001, 1037, (1132), 1306, (1579), (2053), 2070, (3361), 3427, (3919), 3964, 4020,4461, 4561, (4612), 5250 176,248, 547, 628, 684, (786), 794, 797, (922), 938, 1037, (1132), (1307), 1578, 5250 247, 261,377, 380, 547, 581,591,628,636,685, (701), 786, 794, 797, 840, 885,910, 923, 938, 976, 1005, 1030, 1037, 1127, 1132, 1175, 1241, 1244, 1307, 1338, 1386, 1470, 1478, 1535, 1578, 1622, 1699, (1714), 1844, 1864, 1911, 1994, 2067, 2071, (2103), (2124), (2150), (3361), 3394, 3427, (3798), 3919, 4018,4461, (4493), 4560, (4612), 5250 286, 574, 611,623, (688), (799), 822, 876, (903), 993, 1087, 1144, (1208), 1227, (1256), 1270, 1323, 1328, 1422, (1428), (1452), 1456, 1461, 1475, 1513, (1534), (1547), (1565), 1606, 1617, 1665, 1687, (1733), 1738, 1759, 1783, 1789, 1808, 1869, (1897), 1908, 1938, 2023, 2051, 2061, (2076), 2107, 2124, 2142, (2152), (2332), (2371), (2422), 2609, 2663, (2676), (2730), (2955), 3038, 3089, 3462, 4344, (4439), (4460), 4508, 4612, 6125 555, 567, (576), 591,603, 780, 783, 800, 856, 972, 1058, 1066, 1296, 1308, 1350, 1435, 1448, 1493, 1586, (1597), 1669, 1675, 1682, 1687, 1725, 1763, 1847, 1852, 1887, (1910), (1916), 1921, 1948, 2003, 2029, 2033, 2041, (2086), 2104, (2122), (2127), 2186, (2307), (2322), (2337), (2357), 2435, 2511, 2527, 2539, 2558, (2626), 2643, (2674), 2746, (2771), 2963, 3013, 3092, 3360, 3462, 3548, 3566, (3594), 3919, 3984, (4001), (4256), 4344, (4560), (5041), 4612, 5249, 6105 286, 574,611, 623, 628, (800), 822, 876, (903), (993), 1086, (1136), 1144, 1227, (1256), 1270, 1323, 1328, (1386), 1411, 1422, (1429), 1456, 1462, 1475, 1513, (1535), (1538), (1547), 1578, 1606, 1617, (1624), 1645, 1686, (1689), 1731, 1738, 1782, 1789, (1803), 1808, 1869, 1907, (1929), 1936, 1940, (1950), 2023, (2107), 2125, 2142, (2152), (2205), 2332, (2521), 2526, 2546, (2579), (2610), 2663, (2698), 2730, (2763), (2916), 2955, 3036, 3088, 3095, 3361, 3463, 4001, (4019), 4102, 4344,4440,4461, (4493), 4508, 4612, (4664), (4671), (4703), 5040, 5839, 6125 176, (207), 285, 533, 536, 555, 567, (575), 591, 604, 628, 636, 671,783, 856, 867, 913, 974, 980, (1058), 1066, 1170, 1297, 1308, 1349, (1449), 1493, (1597), (1681), (1762), 1852, (1889), (1910), (1922), (2104), 2186, 2558, (3092), (3361), (3461), 3548, 3566, 3919, (4253), (4561), 4612, (5040), 5250 516, 529, 595, 705,782, 1133, 1237, (1327), 1367, 1419, 1441, 1549, 1592, 1644, 1713, 1733, (1778), 1835, 1842, (1855), 1929, (2013), (2029), 2047, (2216), (2693), (3337), (3548), (4508), 4590, 4613, 5249,6031 502, 538, (798), (833), (841), 1160, (1285) 176, 191,466, 529, 596,642, 652, 705, 782, 786, (1115), 1132, 1237, (1276), (1285), 1328, 1367, 1381, 1419, 1441, (1523), 1549, 1592, 1644, 1713, 1733, 1778, (1835), 1841, 1856, (1900), 1929, (2014), 2048, (2069), 2192, 2216, (2233), (2609), 2694, (3125), 3336, 3549, (4190), (4509), 4590, 4612, 5249, 6031 176, 193, 204, 247, 380, 580, 628, 840, 885, 923, 932, 938, 975, 1005, 1037, 1078, 1132, 1175, 1244, 1338, (1422), 1478, 1535, 1578, 1699, 1713, 1871, (1878), (1949), 2071, (2103), (2493), 2941, 3394, 3549, 3426, 3798, 3919, 3961, (4019),4461,4492, 4560, 4612, 5250 408,444, (882), (898), (1136), (1233), (1264), (1957), (2254), (2260), (3459) 428, 463, 636, (671), 694, 729, (784), 903, (1298), (1307), (2039), (4216), 5249
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 335
Table 1 - - continued
Gated y-ray y-Rays observed in coincidence (keY) (keV)
601
607
610 623 628 636
642 671 694
729 751 7820 794 c
888 r
937 1098
1207 1419 1493 1578 2009 3361 3394 3463 3798 3919
3962 3983 4001 4019 4101
4189 4217 4256
428, 497, 518, (610), (678), 894, (1034), 1123, 1126, 1264, 1269, 1296, 1385, 1414, 1425, (1496), 1583, (1590), 1657, (1829), (1933) 408, 412, 425,444,449, 491, 715, 888, 1010, (1090), 1118, 1259, 1327, 1378, 1576, (1949), 2105, (5039) 408,444, 601, (706), 718, 889, 903, 1261, (1298), 1412, (1514), 1960, (4612) 408,444, (586) (286), 377, 380, 465, 546, 601,694, 751, (1252), (1752) (346), 382, 462, 571, (574), 594, (643),649, 687, (695), 765, 981,998, (1029), 1042, 1088, 1161, 1229, 1233, (1247), 1261, 1285, 1338, 1349, 1378, 1389, 1397, (1461), 1474, (1504), 1510, 1548, 1555, (1580), 1600, 1672, 1680, 1708, 1713, 1720, 1743, (1768), 1795, (1850), 1857, (1897), (2018), (2149), 2303, (2319), 2332, 2401, (2423), 2434, 2474, (2504), (2791), (3462), (3577), 4218, 4343, (4350), 4560, 4613 285, 533, 536, 651, (866), 913, (1036), (1169), (2728), 5250 382, 462, 572, (594), (1338), 1555, (1851), (1856), 4343 404, 590, (593), 801,858, 923, 941, 985, 1030, 1170, 1176, 1189, (1227), 1262, 1280, 1320, (1331), (1453), 1497, 1504, 1508, 1522, 1525, 1533, 1542, (1582), (1585), 1622, 1650, 1686, 1710, 1799, 1831, 1839, 1877, 1921, 1947, (2244), (2261), (2274), (2292), (2608), (2863), 3166, 3567, (3578), 4189, 4345, 4855, 5250, 5839 548, 591, (801), 923, 941,985, (1030), (1263), (1498), (1947), (2547), 5249, 5839 176, 248, 628, 938, 1037, (2071), 2900, (3425), (4460), (4560), (4613), 5250 428, 440, 464, 502, 538, 797, 889, (1331), 2196,4460, 5249 176, 204, 220, 361, 370, 375, 380, (637), 687, 694, 786, 882, 889, 1088, 1097, 1330, (1453), (1699), (3920),4459, (4560), 5250 176, 321, 367, 375, 380, 547, 557,607, 623, 702, 785, 794, (852), (1140), (1230), (1320), 3251, 3578, 4612, (5040) 285, 380, (465),547, 751, 1098, 4560, 4612 626, (638), 772, (800), 1139, 1183, (1219), 1435, (1516), 1596, 2480, 2955, (3461), (4002), (4253) 767, 1050, 1830, 502, 538, 4612 428, 463, 4612 380, 547, 602, (751), 3126, 3919 (538), (543), (629), (642), (2447), (2624), 4560 380, (408), 428,444, (464), (794), 1888, (2744), (2764), 3173, 3208 380, 547, (635), 2103, 3139 408, 428,444, (464), (502), (538), (1116), (1207), 2434, 2568, (2643), 2662, 3106 (380),444, 538, 547, (751), 1699, (2233), 2735, 2771 380, 428,444, 464, (537), 547, (1331), (1516), 1578, 1584, (1595), 1920, 2186, (2206), 2614, 2650 380, (408), (428), 547, (795), (1288), 1535, (2571), 2607 (408), (428),444, (538), (1005), 2041, 2047, 2077, (2121), 2142, 2551, (2585) 408, 428,444, 1617, (1839), (1897), 2104, 2124, 2533, 2568 380, (428),444, (502), (537), (592), 888, 1066, 1231, 2013, 2106, 2515, 2550 380, 408, 427, 464, 502,538, 546, 636, 885, 1285, 1419, 1493, 1513, 1795, 1920, 1929, 1956, 2003, 2023, 2430, 2467 408,444, (538), (636), 694, 1650, 1842, (1937), 2380 (408), (444), 636, 1297, 1680, 1908, 2315 (408), (1183), (1263), (1778), (1852), 1870, (2278), 2314
336
Table 1 - - continued
J. Honzdtko et aL /Nuclear Physics A 645 (1999) 331-375
Gated y-ray y-Rays observed in coincidence (keV) (keV)
4343 4439 4460 4492 4508 4560
4591 4612
4855 4899 4916 4982 5039 5249
5304 5840
408, (428), 444, (463), 636, (672), 694, 984, 1555, 1763, 1783, 2190 408, 443, 538, (546), 1058, 1592, 1686, 2094 380, (408), (443), (538), 547, 751, 787, 797, 1037, 1665, 2073, 2108 (380), 547, 1005, (2041), 2077 408, 444, (502), 537, 1617, (2025), 2061 380, 547, 636, 687, (693), (751), (767), 797, 938, (1207), 1338, (1546), (1565), 1471, 1974, 2009 (408), 502, 538, (636), 1441, (1534), 1944, 1978 408, 428, 444, 463, 502, 538, 547, 636, (795), 885, 903, 1285, 1419, 1493, 1513, 1921, 1957 (636), (693), (729), 985, (1042), 1270, 1678, 1714 (408), (444), (941), (1226), 1669 582, (923), (1115) (380), (547), (1144), (1552), 1587 (428), 888, 1086, (1493), (1530) 176, 204, 247, (265), 380, (408), 428, (444), 465, 502, 533, 538, 546, 590, (636), 642, (648), 694, (729), 751,782, 794, 856, 876, 1284, 1319 822, 1230 (193), 285, (408), 538, 694, 729
Coincident transitions resulting from single escape, double escape or some small transitions are not included. Parentheses denote a weak coincidence; bold print denotes a strong coincidence. a Results of a separate short run without a Pb filter between detectors and sample. b Doublet of the 463.3 and 465.6 keV transitions. c Unresolved doublet of the 590.3 and 590.5 keV transitions. d Doublet of the 781.7 and 782.6 keV transitions and a small contribution of the 786.2 and 785.4 keV transitions. e Doublet of the 794.2 and 797.1 keV transitions. f Multiplet of the 888.8, 887.6 and 885.3 keV transitions.
2.2.1. The (d,p) measurements
The (d,p) measurements were performed with 17 MeV deuterons at scattering angles
of 15 ° and 30 °. This, firstly, allows the selection of roughly the low (l = 1,2) and
high (l = 4, 5) angular momenta involved in the reaction and, secondly, partly avoids
the problem of interference of Te peaks with background peaks. The target of 90.7%
enriched 124Te had dimensions of 1 x 4 mm z and a thickness of 40 /zg/cm 2 on a
5 / . t g / cm 2 thick carbon backing. Several spectra (see Fig. 2) were recorded in the range
up to 3.3 MeV by taking seven overlapping runs each about 700 keV wide. The intrinsic
position precision is better than 0.1 mm which made it possible to determine the energy
of the strongest peaks with a precision up to 0.1 keV with an energy resolution of
about 4 keV (FWHM). Each run was calibrated using the proton peaks with l = 1
and the corresponding level energies determined in the thermal neutron capture reaction.
Relative normalization of the individual runs was obtained by a monitor counter (Si
telescope detector) which recorded the elastically scattered particles under a fixed angle
of 40 °. Some minor contamination from other Te isotopes was subtracted using well-
known Q-values and assuming that the relative intensities of contaminant peaks agree
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 337
35000
30000
25000
20000
©
15ooo
10000
5000
0 0
J i , I i
200
' t . D I I I I I t6 ~.
gate 380 keV t 'NI ~ " C I
; m
Lt~ o')
co
- lOx 5~
I I i I , I , I
400 600 800 1000 1200
Channel Number Fig. I. Example of 7~,-coincidence spectrum obtained in thermal neutron capture. Only the lower energy part after background subtraction is shown.
with previously reported values [34-36]. The weighted mean energies from two angles and the corresponding relative intensities of the (d,p) peaks are listed in Table 2.
The experimental (d,p) intensities were compared with the theoretical cross sections calculated by the distorted-wave Born approximation (DWBA) in order to deduce the spectroscopic information. The theoretical calculations were performed with the optical model parameters for deuterons from Ref. [37] and for protons from Ref. [38]. Since
only relative intensities are available in the present studies a link to the calculated absolute intensities is realized by a fitting procedure which was chosen in such a way to obtain the best agreement with spectroscopic factors obtained previously [6,8 ]. This
procedure is reliable up to 2.3 MeV where, in most cases, the /-values are determined
unambiguously. Above 2.3 MeV there are many moderately and weakly populated states for which it is rather difficult to distinguish between/-values if only two angles are used.
Moreover, as mentioned by Rcdland et al. [39], the angular distribution for the weak transitions can only be understood if multistep processes are included in addition to DWBA.
2.2.2. The (3He, oO measurements The (3He,o~) experiment was performed with a 32 MeV He beam under only one
angle of 10 °. The effective thickness of the target was 60 /~g/cm 2. This spectrum (see Fig. 3) was recorded by a large detector in a wide range up to approximately 4.7 MeV. Energies are determined by a polynomial least-squares fit procedure using the
accurate energies of the low-lying states obtained in the (d,p) study. Above 3.3 MeV this energy calibration becomes much less reliable due to the lack of accurate energy points. Therefore, for these energies the intrinsic high position-sensitive precision of
Tab
le 2
Su
mm
ary
of th
e 12
5Te
leve
ls o
bser
ved
in t
he (
n, y
), (
d, p
), (
3He,
or)
rea
ctio
ns a
nd o
ther
stu
dies
0¢
Lev
el
ener
gy
from
se
cond
. y-
rays
(k
eY)
Pres
ent
wor
k L
evel
en
ergy
I~
fr
om
prim
ary
y-ra
ys
(keV
) a
Lev
el
ener
gy
I(15
°)
I(30
°)
from
(r
elat
. (r
elat
. ( d
, p )
c un
its)
un
its)
(k
eY)
1 2
3 4
5 6
0 35
.49(
2)
144.
87(1
) 32
1.11
(2)
443.
53(1
) 46
3.34
(1)
525.
31(1
) 53
7.79
(1)
636.
07(1
)
642.
21(2
) 67
1.43
(1)
729.
22(1
) 78
6.72
(2)
0 13
2 35
.5
271
443.
5 13
3
537.
8 38
.8
729.
2 26
2
1017
.71(
1)
1053
.76(
2)
1066
.42(
2)
1071
.65(
2)
1092
.4(2
) 11
33.1
1(1)
0.1(
2)
652(
15)
35.4
0(20
) 47
7(13
) 14
5.13
(11)
85
(2)
212(
9)
443.
31(3
6)
42(1
) 14
(2)
462.
81(2
9)
5(1)
5(
2)
525.
28(1
2)
16(1
) 15
(3)
537.
74(1
0)
17(1
) 28
(3)
636.
17(9
) 18
(1)
23(3
)
641.
56(1
9)
13(1
) 31
(4)
671.
25(8
) 26
6(3)
17
7(8)
72
9.05
(6)
165(
2)
82(5
) 78
6.78
(8)
79(1
) 88
(6)
804.
61(1
4)
7(1)
4(
2)
1017
.55(
42)
0.5(
1)
1053
.72(
9)
71(1
) 52
(4)
1066
.16(
18)
45(1
) 35
(3)
1133
.11(
10)
73(2
) 54
(5)
1148
.73(
21)
4(1)
7(
2)
Lev
el
ener
gy
Inte
nsit
y fr
om
( i, tb
/ sr
) (3
He,
or)
(keY
)
Oth
er s
tudi
es
(d,p
) l
(t,d
) l
(d,t
) 1
(3H
e, a
) l
Ref
. [6
] R
ef.
[8]
Ref
. [9
] R
ef.
[91
7 8
9 10
36.5
(19)
48
(4)
145.
0(11
) 10
35(4
3)
316.
5(33
) 12
(2)
446.
3(34
) 7(
2)
464(
3)
5(2)
52
0.6(
35)
7(1)
0 35
144
445
463
526
11
12
13
14
0 0
0 0
0 0
0 2
35
2 34
2
35
2 5
144
5 14
5 5
145
5
}639
.4(2
1)
339(
8)
667.
1(30
) 58
(4)
786.
3(35
) 15
(3)
803.
0(35
) 18
(3)
Ado
pted
Ene
rgy
jTr
(keV
)
15
16
17
18
320
(5)
322
(5)
445
2 44
4 2
446
2 46
3 2
463
2 52
6 3
525
3 53
8 (0
) 63
6 4
642
4 64
2 4
642
4 67
1 2
671
2 67
1 2
729
2 72
9 2
729
2 78
6 f
(1+
3)
786
3 78
6 3
0 1/
2 +
~,
35.4
9(2)
3/
2 +
~-
144.
87(1
) 11
/2-
321.
11(2
) 9
/2-
,....,
443.
53(1
) 3/
2 +
"x
463.
34(1
) 5/
2 +
525.
31(2
) 7
/2-
537.
79(1
) 1/
2 +
,.~
636.
07(1
) 7/
2 +
642.
21(2
) 7/
2 +
671.
43(1
) 5/
2 +
'...n
729.
22(1
) 3/
2 +
786.
72(2
) 7
/2-
"~
',o
804.
61(1
4)
15/2
- t.~
804 a
524
(3)
}640
671
2
}795
g
843
1026
.0(4
2)
3(1)
10
54.3
(12)
56
(3)
1086
.3(2
5)
6(1)
11
35.7
(14)
38
(4)
1115
2.9(
17)
26(3
)
1055
10
17
3 10
55
3 10
53
2 10
65
2
1089
2
1133
(2
) 11
33 f
2 11
32
2
1147
4
1054
2
}113
6 2-
t-4
1017
.71(
1)
3/2
+,5
/2,7
/2 +
,.~
10
53.7
6(2)
5/
2 +
1066
.42(
2)
3/2
+,5
/2 +
10
71.6
5(2)
(5
/2-)
10
92.4
(2)
(3/2
+,5
/2 +
) 11
33.1
1(6)
(5
/2 +
)
1148
.7(2
) 7/
2 +
(9/2
+ )
1191
.7(3
) /
(11/
2 +
)
Tab
le 2
(c
onti
nued
) l
2 3
4 5
6
1209
.73(
2)
1242
.94(
4)
1245
.94(
13) I
12
65.1
6(2)
1314
.6(2
) 13
19.5
3(2)
13
22.4
2(3)
13
57.4
7(16
) 14
35.8
9(3)
.152
1.3(
2)
1529
.66(
5)
.158
0.8(
1)
1587
.28(
2)
1652
.53(
5)
1670
.16(
3)
1699
.93(
2)
1713
.52(
2)
1732
.4(2
) 17
59.4
9(9)
17
66.4
5(3)
17
71.1
6(5)
,1
775.
0(1)
18
13.0
2(26
)
1243
.0
16.3
1265
.3
35.7
1319
.7
918
1435
.5
5.6
1529
.6
43
1587
.4
75
1652
.7
31
1670
.5
25
1204
(1)
3(1)
12
43.3
(4)
12(2
) e
6(2)
1265
.15(
20)
30(4
) e
29(3
)
1315
.03(
35)
2(1)
5(
2)
1319
.71(
13)
17(1
) 19
(3)
1357
.62(
19)
3(1)
8(
2) e
14
35.8
1(10
) 22
(1)
19(3
)
1520
.3(5
) 0.
5(2)
1529
.85(
9)
17(1
) 10
(1)
1581
.0(4
) 1.
5(2)
1587
.20(
10)
18(1
) 44
(2)
1652
.4(4
) 1.
0(2)
2(
1)
1670
.5(6
) 0.
9(2)
7 8
9
1237
.0(2
0)
10(2
)
1264
.8(1
3)
54(3
) 12
65
1315
.6(1
3)
60(3
)
1357
.8(1
4)
29(2
) 14
34.5
(14)
31
(3)
1435
lO
II
12
13
14
15
16
1242
l
1241
2
1265
2
1263
2
1261
2
1309
4
1309
4
1317
0
1322
2
1364
5
1355
4
1355
4
1435
2
1433
2
1434
2
}152
7.2(
10)
14(2
) }1
526
2 }1
526
2 15
30
1530
2
}158
3.4(
19)
10(2
) !
1643
.3(2
6)
5(1)
1661
.5(2
6)
4(2)
1583
(0
+5)
15
84
0 15
84
(0)
1583
0
1645
2
}165
4 (2
+5)
16
66
(2)
1699
.3
7.3
1713
.8
81
(176
0)
26
1700
.09(
14)
45(1
) 48
(3)
1715
.7(5
) 1.
3(2)
1759
.78(
27)
4.3(
3)
1770
.59(
27)
4.4(
3)
1813
.00(
32)
46(2
) 11
(2)
1820
.18(
22)
75(3
) 51
(3)
1824
(1)
3.9(
8)
1698
.9(2
6)
4(2)
16
98
1 16
98 (
1)
1695
1
1710
0
}172
5.8(
14)
77(4
) 17
27
4 17
30
4 17
54
2 17
55
2 }1
757.
7(19
) 13
(2)
1770
(0
) 18
13.8
(28)
14
(4)
1809
2
1826
.4(2
8)
11(3
)
}181
6 (3
) 18
16
3 }1
819
2+4
17
18
1209
.73(
2)
(5/2
-,7
/2 +
) 12
42.9
4(4)
1/
2+,3
/2,5
/2 +
,1
245.
9(1)
(5
/2 +
) 12
65.1
6(2)
3/
2 +
1310
.2 i
1314
.63(
17)
7/2
+,9
/2 +
13
19.5
3(2)
3
/2-
1322
.42(
3)
5/2
-,7
/2-
1357
.53(
12)
7/2+
,9/2
+
1435
.89(
3)
5/2
+ 15
00.5
i 19
/2-
1521
.16(
24)
(3/2
+),
5/2
+
1529
.71(
6)
3/2
+ 15
70.i
(3) i
(1
5/2
+ )
1580
.8(1
) 1/
2,3/
2,5/
2
1587
.28(
2)
1/2 +
1652
.53(
5)
3/2
+
1670
.16(
3)
3/2
+ 16
99.9
3(2)
3
/2-
1713
.52(
2)
1/2 +
t7
32.2
(4)
7/2+
,9/2
+
1759
.5(1
) 3
/2+
,(5
/2 +
) 17
66.4
5(3)
(3
/2-)
,5/2
,(7
/2 +
) 17
71.1
6(5)
,1
775.
0(1)
(1
/2 +
) 18
13.0
(3)
3/2+
,~5/
2 +
)
1820
.2(2
) (5
/2-,
7/2
-)
0,
,.,,..
7"
Tab
le 2
(c
ontin
ued)
1
2 3
4 5
6 7
8 18
32.3
(6)
1865
.12(
4)
1899
.00(
5)
1904
.90(
3)
1911
.1(1
) 19
18.5
5(3)
19
32.0
8(9)
19
56.7
4(3)
.1
968.
9(3)
19
78.7
6(3)
.1
982.
2(4)
~1
991.
0(1)
19
95.0
(1)
2009
.33(
3)
2020
.44(
9)
,204
7.1(
1)
2049
.51(
6)
2061
.02(
3)
*206
8.7(
3)
2076
.95(
5)
,208
7.0(
1)
2108
.58(
4)
2129
.60(
3)
2132
.03(
13)
2145
.5(2
) 21
50.1
(1)
1865
.2
61
1899
.7 (
35)
1905
.1
68
1956
.7 2
022
1978
.4 3
04
2009
.2
883
2049
.4
21
2060
.8
129
2077
.1
137
2108
.6
380
2129
.7
296
2145
.0 (
15)
1863
.4(5
) e
8.2(
12)
1888
(1)
1.4(
6)
1905
.2(6
) e
4.4(
1)
1918
.6(8
) 2.
0(7)
19
29.4
(5)
e 54
(10)
e
1956
.72(
15)
82(3
) 66
(14)
e
1982
.3(4
) 78
(2)
80(5
) e
1994
.6(4
) 6.
2(7)
39
(16)
e
2009
.77(
22)
25(1
) 18
(9)
2049
.14(
23)
187(
2)
236(
6)
2061
.4(4
) 2.
1(4)
2079
.5(3
) 4.
7(4)
6.
0(13
)
2112
.47(
31)
407(
3) 6
89(1
0)
2126
.80(
32)
118(
2)
262(
6)
2153
.43(
39)
7.1(
5)
e
1885
.5(2
8)
7(2)
}190
9.0(
19)
23(4
)
1922
.0(2
8)
12(3
)
1968
.2(2
1)
11(2
)
}200
7.1(
14)
20(3
)
2044
.9(3
0)
6(2)
2082
.2(1
4)
19(2
)
}210
4.8(
29)
6(2)
2159
.9(2
1)
11(2
)
10
11
12
13
14
1832
4
1853
2
1857
2
1881
19
00
0
1926
2
}192
5 (3
) 19
25
3 19
54
1 19
54
(1)
1951
1
1969
4
1978
(2
) 19
78
3 19
85
0
}200
8 (1
+5)
20
05
l 20
05
(1)
2044
1
2044
1
2042
I
2058
2
}210
5 f
(1+
3)
2080
(4
)
2105
f (3
) 21
03
(3)
2121
2
2147
(0
)
2157
(4
)
15
16
17
18
}190
7 (0
+4)
1969
4
}201
0 5
2085
(4
)
1832
.3
7/2+
,9/2
+
1865
.12(
4)
3/2
+
1899
.00(
5)
(3/2
+ )
1904
.90(
3)
(3/2
+ )
1911
.1(I
) 7/
2 +
1918
.55(
3)
(1/2
+),
3/2+
,5/2
+
1932
.1(1
) 5
/2,7
/2-
1956
.74(
3)
3/2
- 19
68.9
(3)
7/2+
,9/2
+
1978
.76(
3)
1/2{
-),3
/2 (-
} 19
82.3
(2)
(3/2
),5/
2-
1991
.0(1
) 1/
2 +
1994
.9(1
) (9
/2-)
2009
.33(
3)
3/2
- 20
20.4
4(9)
3/
2+,5
/2,7
/2 +
,2
047.
1(1)
20
49.5
1(6)
3/
2 20
61.0
2(3)
3/
2 +
~206
8.7(
3)
2076
.95(
5)
1/2
-,3
/2
2079
.5(3
) (7
/2+
,9/2
+ )
2087
.0(1
) 1/
2,3/
2,5/
2 +
2108
.58(
4)
(1/2
-),3
/2-
2112
.5(3
) (5
/2-,
7/2
-)
2126
.8(3
) (h
) 21
29.6
0(3)
1
/2-,
3/2
21
32.0
(1)
3/2+
,5/2
,7/2
+
2145
.5(2
) (1
/2}+
, 3/
2 21
50.1
(1)
3/2,
5/2
+ 21
59.9
(21)
(7
/2+
,9/2
+ )
e~
'.n
Tab
le 2
(c
ontin
ued)
1
2 3
4 5
6 7
8
.217
6.0(
2)
2181
.93(
6)
2204
.09(
4)
2220
.2(2
) 22
26.1
8(5)
22
32.6
(3)
2246
.51(
6)
2251
.11(
9)
2270
.83(
6)
,229
2.9(
1)
,231
0.75
(10)
23
13.5
4(11
) 23
15.6
4(11
)
2351
.66(
6)
2372
.6(1
)
2379
.47(
6)
2384
.1(2
)
2410
.1(1
)
2415
.6(1
)
2438
.7(2
)
2466
.59(
3)
2176
.1
24
2181
.9 (
35)
2204
.3
34
2220
.1
56
2226
.2
395
2246
.7
46
2251
.0
33
2271
.3
62
2313
.5 (
54)
2315
.6
161
2351
.4
150
2379
.7
265
2410
.0
48
2415
.1
57
2439
.7 (
43)
2466
.0
253
2187
.7(4
) 20
(1)
102(
14) e
2206
.9(5
) 2.
5(4)
2223
.9(4
8)
1.4(
4)
2250
.1(4
) 54
(2)
79(1
1) e
2274
.2(4
) 9.
6(6)
22
82.6
(4)
5.9(
5)
2293
.65(
41)
4.2(
8)
2315
.6(4
) 1
79
(3)
269(
15) e
23
32.6
5(30
) 35
(1)
96(1
4) e
2351
.65(
31)
24(1
)
2375
.41(
26)
8.2(
5)
14(2
) 23
81.9
8(34
) 4.
9(4)
2391
.11(
29)
8.4(
6)
12
(1)
}241
2.3(
3)
3.5(
4)
3.8(
5)
2419
.05(
30)
8.1(
7)
12.1
(7)
2426
.2(6
) 2.
8(3)
24
39.2
9(29
) 2.
7(3)
24
50.6
1(28
) 4.
2(4)
5.
3(5)
24
65.8
4(29
) 12
.0(7
) 14
.5(7
)
2189
.5(2
1)
12(2
)
2225
.8(3
0)
7(2)
2259
.4(2
4)
9(2)
2316
.5(3
1)
10(2
)
2364
.4(3
0)
8(2)
2388
.8(2
6)
8(2)
2427
.2(3
5)
7(2)
2449
.1(3
0)
9(2)
9 10
11
12
2178
f (1
+3)
21
78
1
2244
1
2244
1
2268
22
73 (
1)
2282
)231
1 1
2311
1
}234
6 23
46 (
3)
2376
3
13
14
15
2175
(0)
2197
(4)
2221
(2
)
16
17
18
21
76
.0(2
) 1/
2(+
),3/
2 21
81.9
3(6)
1/
2,3/
2 i2
183
(4)
21
87
.7(4
) (7
/2+
,9/2
+ )
2204
.09(
4)
1/2
-,3
/2
2219
.4(2
) 3/
2 +
22
26.1
8(5)
3/
2 (-
) 22
32.6
(3)
2246
.51(
6)
1/2
-,3
/2-
22
51
.1(1
) 1/
2+,3
/2
2259
.4(2
4)
2270
.83(
6)
1/2+
,3/2
22
82.6
(4)
2293
.1(2
) (5
/2)
2310
.7(1
) 1
/2+
,3/2
,(5
/2 +
) 23
13.5
4(11
) 1/
2+,3
/2
2315
.6(1
) 3
/2-
2332
.7(3
)
2351
.66(
6)
(1/2
+),
3/2
23
72.6
(1)
1/2
+,3
/2,5
/2 +
23
75.4
(3)
5/2
-,7
/2-
2379
.47(
6)
3/2
- 23
84.1
(2)
(1/2
+),
3/2
,5/2
23
91.1
(3)
(h)
2410
.1(1
) 3/
2
24
15
.6(1
) 1/
2+,3
/2
2419
.1(3
) 24
26.2
(6)
(h)
2438
.84(
19)
1/2+
,3/2
24
50.6
(3)
h 24
66.5
8(5)
1/
2+,3
/2
? =z e5
%n ?
Tab
le 2
(con
tinu
ed)
2495
.4(1
) I
~250
4.2(2
)1
~25
21.4
(1)
~25
28.6
(1)
2 3
2494
.5
62
(28)
4 5
6 7
8 9
10
11
12
13
14
15
16
2479
.06(
29)
2.2
3.2(
4)
2488
.36(
29)
10.4
13
.9(7
)
2495
.0(4
) 2.
9(4)
3.
9(5)
24
91.8
(35)
4
(2)
2521
.0(4
) 16
.1
20.8
(9)
2518
1
2525
.7(5
) 2
.4(7
) 25
29.6
(35)
7
(2)
* -
Ten
tati
ve l
evel
.
a _
Ene
rgie
s de
duce
d fr
om t
he n
eutr
on b
indi
ng e
nerg
y of
656
8.97
5:0.
03
and
the
ener
gy o
f th
e pr
imar
y y-
rays
. b
_ In
tens
itie
s of
the
pri
mar
y y-
rays
cor
rect
ed t
o th
e E
5
(MeV
) .
c _
Ave
rage
d va
lue
of 1
5 °
and
30 °
mea
sure
men
ts.
d .
Ref
. [3
9]
sugg
este
d j~
r =
15
/2-
from
com
bine
d C
CB
A a
naly
sis.
e
_ P
ertu
rbed
by
a br
oad
back
grou
nd p
eak.
[ -
Pos
sibl
e do
uble
t.
g -
Pos
sibl
e do
uble
t of
7/2
- an
d 1
5/2
- st
ates
.
h .
Hig
h an
gula
r m
omen
tum
tra
nsfe
r in
(d
,p)
and
(3H
e, a
) re
acti
ons
i .
Fro
m (
a, 3
ny
) st
udie
s R
ef.
[5]
.
J -
Sup
erim
pose
d on
to e
scap
e pe
ak.
k _
Bas
ed o
n th
e su
m-c
oinc
iden
ce m
easu
rem
ents
Ref
. [4
41.
17
18
2479
.1(3
)
2488
.4(3
) 24
95.4
(1)
3/2
2504
.2(2
) 1
/2+
,3/2
25
21
.4(I
) 3
/2-
2525
.7(5
) e~
R
- 7"
t~
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 3 4 3
~ 5 0 -
O I--
I'~ t.¢) ~ ti~t. ~ t .~, ~ -
O" . . - ~ . - i . . ~ t , t ~
0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0
C t l A N N E L 8 0 0 , , , , - ,
6OO
c
4 0 0 !
0
('~ I °'3 ('° "~1" rn 03 2 0 0
t
0
, i i O 2 0 0 4 0 0 6 0 0 8OO 1 OOO 1 2 0 0
C I ] A N N E L
F ig . 2. Parts o f the ] 2 4 T e ( d , p ) 1 2 5 T e spec t ra measu red at E d = 17 M e V and ~ = 30 ° ( t o p ) and at
(-) = 15 ° (bottom).
the large detector could not be fully realized. An energy resolution of about 18 keV (FWHM) for the single o~-peaks at lowest excitations was obtained. A few contaminant peaks from other Te isotopes were identified by comparison with the calculated energies using the Q-values from the Wapstra tables and the known spectroscopic information on
tellurium isotopes. The absolute cross sections were determined by measuring the total beam current into a Faraday cup. Energies and cross sections are presented in columns 7
and 8 of Table 2. A comparison of our intensities at 32 MeV with those at 24 MeV reported in Ref. [ 9 ]
shows a good proportionality, although there is a certain tendency to increase faster at 32 MeV for transitions with higher/-values. This feature provides the possibility for a direct estimation and, in some cases, of unresolved peaks at 24 MeV for a correction of S-factors without carrying out DWBA calculations. In spite of the superior energy resolution the complexity of the a spectrum increases quickly above 2 MeV, eventually producing an almost continuous distribution with only a few discrete structures. Con- cluding this section we would like to point out that the complete set of experimental
344 J. Honzttko et al./Nuclear Physics A 645 (1999) 331-375
100
80
6o
0 L~ 40
20
~26Te(3He,ct)~2STe, E=32 MeV, Theta=10 ° , ! !
~o ~ ~
I I
o
~D
w
¢OClD
~,..~ ~i
, !
o
I
J
0 800 1000 1200 1400 1600 1800 2000
CHANNEL
Fig. 3. The or-energy spectrum from the ]26Te(3He,c~)J25Te reaction measured at EHe = 32 MeV and at ~) = 10 °. The high energy part in the insert shows transitions from discrete structures of predominantly hole valence subshells to the nearly structureless continuum arising from deep inner-hole states. The dashed line represents our assumption about the background of underlying continuum taken from Ref. [45] of neighboring Te isotopes corrected for Q-dependenee.
data obtained in the present complex study is given in Ref. [40] .
3. The level scheme
The level scheme of ]25Te was deduced from the present complex studies in com-
bination with the available data compiled in Ref. [41] . The construction of the level
scheme in the present work was essentially based on coincidence data. The arguments
for the inclusion of levels in the scheme were:
( i ) evidence of population in the nucleon transfer reactions, or
( i i) evidence of primary feeding in the thermal neutron capture reaction and at least
one deexcit ing transition supported by a coincidence relation, or
( i i i ) evidence of secondary transitions in three or more independent gates or sum-
coincidence spectra with sufficient statistics (three statistical errors or more) .
Levels of lower statistical confidence are assumed to be uncertain. A few levels,
mostly of high spins, are also included, since they could be tentatively observed in the
(3He,ce) spectrum. The present level scheme considerably extends the previous scheme
of Ref. [41] in terms of the energy accuracy, the number of transitions placed and J~
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 345
assignments made.
Spin-parity assignments and limits are derived from all available data. The general criteria were:
(i) for levels populated by primary transitions the J~" values are assumed to be 1/2 +-
or 3/2 ±, (ii) it is assumed that no M2 (or higher multipolarity) transitions are observed.
Criterion (i) is supported in the present measurements by the observation of only a
few E2 primaries populating the lowest well-known 5/2 + states. For several levels the spin assignment was made on the basis of a Monte Carlo simulation of the statistical
population. Final level energies, other than those established in the nucleon transfer reactions,
were determined by a least-squares fit procedure [42] in which the criterion for y-ray
acceptance was that the deviation between the level energy and the transition energy
was within 2.5 times the statistical error. In such a way the neutron separation energy of t25Te was determined to be 6568.97 ± 0.03 keV. A list of levels included in the energy
region 0-2525 keV, where the most complete spectroscopic information was collected from the present work and from previous studies, is given in Table 2. Adopted energies and spin-parities are listed in the last two columns. Data on other levels above 2525 keV,
which are not included in Table 2, can be found elsewhere [40]. The branching ratios
derived from the analysis of both the singles and coincidences data are listed in Table 3.
3.1. Individual level description
Levels below 700 keV have already been well established from the previous spectro- scopic studies. Therefore, in the following description, only new levels or those which
received new assignments are considered.
The 729.22 and 786.72 keV levels
Unambiguous spin assignments have been found in this work for the low-lying levels
at 729 and 786 keV, 3/2 + and 7 / 2 - , respectively, confirming the spin assignments given
in Ref. [9].
The 1017.71 keV level
This level, previously seen only in the (d,t) reaction and tentatively assigned [9] as
the 1 I / 2 - state in the present studies, is observed also as a weakly populated (d,p) peak which is depopulated via three y-transitions in the (n,y) reaction limiting spin-parity
assignment to 3/2, 5 /2 and 7/2 + .
The 1053.76 keV level
The sharp disagreement between the two/-values of 2 and 3 and the consequent possi- bility of the existence of two close-lying levels [41 ] can be resolved in the present work.
346 J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
Table 3 Gamma decay of the observed levels in 125Te
Ei jrr (keV)
Ey Branching Ef (keY) (keV)
j~r
463.34(1) 5/2 + a
525.31(1) 7 / 2 - a
537.79(1) (1/2 + ) a
636.07(1) 7/2 + a
642.21(2) 7/2 + a
671.43(1) 5/2 + a
729.22(1) 3/2 +
786.72(2) 7 / 2 -
1017.71(1) 3 / 2 + , 5 / 2 , 7 / 2 +
1053.76(2) (3/2 + ) ,5 /2 +
1066.42(4) 3 /2+ ,5 /2 +
321.11(2) 9 / 2 - a 443.53(1) 3/2 + a
35.49(2) 3/2 + a 144.87(1) 11/2- a
35.49 a 100 0.0 1/2 + 109 a 100 35.49 3/2 +
144.78 a 0.00014 a 0.0 1/2 + 176.30 100 144.87 11/2- 443.53 100 0.0 1/2 + 408.04 58.8 35.49 3/2 + 463.35 36.8 0.0 1/2 + 427.85 100 35.49 3/2 + 19.9 a 0.07 a 443.53 3/2 +
380.44 100 144.87 11/2- 204.14 21.4 321.17 9 / 2 - 537.79 100 0.0 1/2 + 502.30 56.7 35.49 3/2 + 600.58 100 35.49 3/2 + 314.9 a 0.02 a 321.11 9 / 2 - 172.7 a 1.11 a 463.34 5/2 + 110.9 a 0.01 a 525.31 7 / 2 - 606.70 100 35.49 3/2 + 497.4 a 0.17 a 144.87 11/2- 321.06 9.3 321.17 9 / 2 - 198.6 a 0.27 a 443.53 3/2 + 178.8 a 0.57 a 463.34 5/2 + 116.61 5.08 525.31 7 / 2 - 671.43 16.3 0.0 1/2 + 635.91 100 35.49 3/2 +
227.91 e 1.2 443.53 3/2 + 208.09 e 2.1 463.34 5/2 + 146.1 a 0.01 a 525.31 7 / 2 - 729.22 27.3 0.0 1/2 + 693.72 100 35.49 3/2 +
285.57 m ~ 8 . 3 443.53 3/2 + 191.43 2.5 537.79 (1/2 + ) 641.85 59.4 144.87 11/2- 465.55 100 321.17 9 / 2 - 261.42 7.9 525.31 7 / 2 - 574.t7 100 443.53 3/2 + 554.39 46.3 463.34 5/2 + 346.34 11.2 671.42 5/2 +
1018.36 e 33.3 35.49 3/2 + 610.22 100 443.53 3/2 +
590.39 m 52 463.34 5/2 + 516.69 4.3 537.78 (1/2 + ) 411.55 17.4 642.21 7/2 + 382.1 c 671.42 5/2 +
1066.29 m ~ 112 0.0 1/2 + 622.88 100 443.53 3/2 + 603.4 c ~ 5 0 b 463.34 5/2 + 528.63 71.9 537.79 (1/2 + ) 424.6 c 642.21 7/2 +
394.63 e 6.8 671.42 5/2 +
1 2 3 4 5 6
I Honz6tko et aL/Nuclear Physics A 645 (1999) 331-375 347
Table 3 - - continued
l 2 3 4 5 6 19.6 1071.65(2) 5 / 2 -
1092.4(2) 3 / 2 + , 5 / 2 +
1133.11(1) (5/2 + )
1209.73(2) 5 / 2 - , 7 / 2 +
1242.94(4) 1 /2+ ,3 /2 ,5 /2 +
1245.94(13)* (5/2 + )
1265.16(2) 3/2 +
1314.55(20) 7 /2+ ,9 /2 +
1319.53(2) 3 / 2 -
1322.42(3) 5 / 2 - , 7 / 2 -
1357.47(16) 7 /2+ ,9 /2 +
1435.89(3) 5/2 +
1521.3(2)*
750.68 628.4 c
546.56 1 O0 285.37 m < 15.2 629.63 c 449.18 100 1097.63 I O0
(688.09) c
595.78 11.6 497.35 3.1 490.94 c
461.69 30.9 403.86 11.9 888.56 1 O0 684.40 19.1
1242.92 e 39.3 1207.29 m'e < 100 (799.27) m 10
779.7 c
704.94 19.0 571.37 8.4 782.8 c 610.2 c
574.17 m
1229.67 100 821.58 13.1 593.58 9.9 193.3 c
(641.85)" _< 100 678.5 c
1319.53 m < 11.7 1284.22 m < 15.0
875.85 2.9 794.22 1 O0
781.84" < 36.4 64-8.01 1.5
590.39 m 9.4 532.9 15
264.34 0.7 247.67 13.1 1001.30 59.5 797.11 29.7 535.81 100 716.24 100
686.67 m 1400.40 e 1 O0 992.39 19.8 972.51 14.9 911.04 6.1 764.34 9.0 706.59 c
1057.50 m 100
321.17 443.53 525.31 786.72 463.34 642.2 l 35.49
443.53 537.79 636.07 642.21 671.42 729.22 321.17 525.31
0.0 35.49
443.53 463.34 537.79 671.43 463.34 636.07 671.43 35.49
443.53 671.43 1071.65 671.43 636.07
0.0 35.49
443.53 525.3 I 537.79 671.43 729.22 786.2
1053.76 1071.65 321.17 525.31 786.72 642.21 671.43 35.49
443.53 463.34 525.31 671.42 729.22 463.34
9 / 2 - 3/2 + 7 / 2 - 7 / 2 - 5 /2 + 7/2 + 3/2 + 3/2 +
( 1/2 + ) 7/2 + 7/2 + 5/2 + 3/2 + 9 / 2 - 7 / 2 - 1/2 + 3/2 + 3/2 + 5/2 +
( I /2 + 5/2 + 5/2 + 7/2 + 5/2 + 3/2 + 3/2 + 5/2 + 5 / 2 - 5/2 + 7/2 + 1/2 + 3/2 + 3/2 + 7 / 2 -
( I / 2 + ) 5/2 + 3/2 + 7 / 2 - 5/2 + 5 / 2 - 9 / 2 - 7 / 2 - 7 / 2 - 7/2 + 5/2 + 3/2 + 3/2 + 5/2 + 7 / 2 - 5/2 + 3/2 + 5/2 +
348 J. Honz6tko et al./Nuclear Physics A 645 (1999) 331-375
Table 3 - - continued
1 2 3 4 5 6 1529.66(5) 3/2 +
1580.8(1)* 1587.28(2) 1/2 +
1652.53(5) 3/2 +
1670.16(3) 3/2 +
1699.93(2) 3 / 2 -
1713.52(2) 1/2 +
1732.2(4) 7 /2+ ,9 /2 + 1759.49(9) 3 /2+ ,5 /2 +
1766.45(3) 3 / 2 - , 5 / 2 , 7 / 2 +
1529.89 c 0.0 1/2 + 1493.30 100 35.49 3/2 + 1086.05 36.7 443.53 3/2 +
1066.29 m 463.34 5/2 + 894.78 2.5 636.07 7/2 + 887.11 28.9 642.21 7/2 +
801.17 m < 5.7 729.22 3/2 + 1137.28 I00 443.53 3/2 + 1587.27 100 0.0 1/2 + 1551.76 10.5 35.49 3/2 + 1143.91 13.0 443.53 3/2 + 858.46 5.5 729.22 3/2 + 1209.59 20.3 443.53 3/2 +
1127.25" < 23.1 525.31 7 / 2 - 1115.23 24.8 537.79 (1/2 + )
1010.53 m < 18.3 642.21 7/2 + 981.71 29.0 671.42 5/2 + 923.29 100 729.22 3/2 +
866.33 c 786.72 7 / 2 - 585.88 12.4 1066.42 3 /2+ ,5 /2 + 580.43 14.1 1071.65 5 / 2 - 1669.89 87.9 0.0 1/2 + 1634.45 e 20.2 35.49 3/2 + 1227.10 'n 100 443.53 3/2 + 1132.37 '1' 56.5 537.79 (1/2 + ) 1034.0 c 636.07 7/2 + 998.49 48.4 671.43 5/2 + 940.94 72.6 729.22 3/2 + 1255.43 10.4 443.53 3/2 + 1029.33 17.8 671.43 5/2 + 913.13 38.0 786.72 7 / 2 - 628.07 100 1071.65 5 / 2 -
1713.43 m < 41.4 0.0 1/2 + 1678.17 s 51.4 35.49 3/2 + 1269.94 79.7 443.53 3/2 + 1042.12 65.2 671.43 5/2 + 984.33 100 729.22 3/2 + 1090.3 c 100 642.21 7/2 +
1296.73 m 463.34 5/2 + 1123.28 636.07 7/2 + 1118.0 c 642.21 7/2 +
1087.36 m 671.42 5/2 + 1030.92 m 729.22 3/2 +
705.8 c 1053.76 5/2 + 626.47 1133.11 (5/2 + ) 1322.79 100 443.53 3/2 + 979.84 55.5 786.72 7 / 2 - 712.2 c 1053.76 5/2 + 633.7 c 1133.11 (5/2 + ) 556.73 66.6 1209 .73 5 / 2 - , 7 / 2 +
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 349
Table 3 - - continued
1 2 3 4 5 6 1771.16(5)
1775.0" 1/2 +
1813.0(3) 3 / 2 + , ( 5 / 2 + )
1832.32 7 / 2 + , 9 / 2 +
1865.12(4) 3 /2 +
1899.00(5) ( 3 / 2 + )
1904.90(3) ( 3 / 2 + )
1911.1(I) 7 /2 +
1918.55(3) 3 / 2 + , 5 / 2 +
1932.1(I) 5 / 2 - , 7 / 2 -
1956.74(3) 3 / 2 -
1735.39 e 44.5 35.49 3 /2 +
1327.20 100 443.53 3 /2 + 1307.26 m 463.34 5 /2 +
637.7 c 1133.11 ( 5 / 2 + )
1237.18 100 537.79 ( 1 / 2 + ) 1349.71 m 463.34 5 /2 +
1276.1 c 537.79 ( I / 2 + )
1307.26 m 525.31 7 / 2 - 1160.78 m 671.42 5 / 2 +
622.88 m 1209.73 5 / 2 - , 7 / 2 +
1865.10 100 0.0 I / 2 + 1829.68 m's < 51 35.49 3 /2 ~
1421.57 41.5 443.53 3 /2 +
1327.20 m 537.79 ( I / 2 + )
799.27 m 1066.42 3 / 2 + , 5 / 2 +
1863.64 s 100 35.49 3 /2 +
1455.42 58.3 443.53 3 /2 +
1435.91 13.6 463.34 5 /2 + 1263.9 c 636.07 7 /2 +
1258.3 c 642.21 7 /2 + 1170.42 m 729.22 3 /2 +
1905.38 ~ 100 0.0 1/2 + 1461.36 m < 91.4 443.53 3 /2 +
1367.17 40.9 537.79 ( 1 / 2 + ) 1269.94 m < 60.2 636.07 7 /2 +
1175.46 m < 54.9 729.22 3 /2 +
771.64 10.7 1133.11 ( 5 / 2 + )
1448.16 m < 72.1 463.34 5 /2 +
1385.82 76.6 525.31 7 / 2 -
839.19 57.9 1071.65 5 / 2 - 701.58 100 1209.73 5 / 2 - , 7 / 2 -
1919.55 '''e 91.7 0.0 I / 2 +
1882.45 e 55.4 35.49 3 /2 +
1475.03 100 443.53 3 /2 + 1381.1 c 537.79 (1 /2 + )
1247.65 7.5 671.42 5/2 + 1189.28 51.7 729.22 3 /2 ÷
1296.73 m 636.07 7 /2 + 1261.00 m 671.42 5 / 2 +
915.95 1017.71 3 / 2 + , 5 / 2 , 7 / 2 ~ 799.27 m 1133.11 (5 /2 + )
1956.73 100 0.0 1/2 ~ 1921.59 m < 15.7 35.49 3 /2 -+
1513.33 17.2 443.53 3 /2 +
1493.30 28.2 463.34 5 /2 + 1418.89 21.7 537.79 ( I / 2 + )
1284.22 m < 16.3 671.42 5 /2 + 1227.10 m < 9.4 729.22 3 /2 + 1170.42 4.1 786.72 7 / 2 - 903.18 1.9 1053.76 5 /2 + 884.94 4.8 1071.65 5 / 2 - 636.7" 1319.53 3 / 2 -
350
Table 3 - - continued
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
1 1968.9(3)
1978.76(3)
1982.2(4)* 1991.0(1)
1995.0(1)
2009.33(3)
2020.44(9)
2047.1(1)* 2049.51(6)
2061.02(3)
2068.7(3)*
2076.95(5)
2087.0(1)* 2108.58(4)
2
7 /2+ ,9 /2 + 1 / 2 ( - ) , 3 / 2 ( - )
5 / 2 - 1/2 +
( 9 / 2 - )
3 / 2 -
3 / 2 + , 5 / 2 , 7 / 2 +
3/2 +
3/2 +
1 / 2 - , 3 / 2
1 / 2 - , 3 / 2 -
3 4 5 6 1327.2 m 100 642.21 7/2 + 1978.76 100 0.0 1/2 + 1942.8 20.0 35.49 3/2 +
1535.02 m < 23.0 443.53 3/2 + 1440.94 m < 98.0 537.79 (1/2 + ) 907.31 10.7 1071.65 5 / 2 - 1538.70 100 443.53 3/2 +
1547.03 c 443.53 3/2 + 1262.15 100 729.22 3/2 + 785.51 m 1209.73 5 / 2 - , 7 / 2 + 923.29 m 1071.65 5 / 2 - 1470.6 525.31 7 / 2 -
2009.28 100 0.0 1/2 + 1973.92 12.5 35.49 3/2 + 1565.91 6.4 443.53 3/2 + 1545.76 6.1 463.34 5/2 + 1470.64 2.0 537.79 (1/2 + )
1338.06 m < 13.4 671.42 5/2 + 937.47 19.8 1071.65 5 / 2 - 766.71 4.3 1242.94 1 /2+ ,3 /2 ,5 /2 +
687.19 ¢ 1322.42 5 / 2 - , 7 / 2 - 1578.04 m 443.53 3/2 + 1384.8 c 636.07 7/2 +
1349.71 m 671.42 5/2 + 975.41 m 100 1071.65 5 / 2 - 1605.99 100 443.53 3/2 + 1585.5 c 463.34 5/2 +
1412.60 m < 41.3 636.07 7/2 + 1378.66 51.7 671.42 5/2 +
1319.53 m 729.22 3/2 + 995.44 e 19.7 1053.76 5/2 +
2060.67 m < 22.0 0.0 1/2 + 2025.52 15.1 35.49 3/2 + 1617.51 100 443.53 3/2 + 1597.13 c 463.34 5/2 + 1522.38 m < 15.5 537.79 (1/2 + ) 1424.86 12.7 636.07 7/2 +
1388.19 m < 9.1 671.42 5/2 + 1331.39 c 729.22 3/2 + 851.87 8.0 1209.73 5 / 2 - , 7 / 2 + 1623.56 43.9 443.53 3/2 + 1397.49 100 671.42 5/2 +
2077.04 s 100 0.0 1/2 + 2041.46 s 32.3 35.49 3/2 +
1005.2 14.3 1071.65 5 / 2 - 1549.16 100 537.79 (1/2 + ) 2108.41 63.7 0.0 1/2 + 2073.07 68.3 35.49 3/2 + 1664.74 29.4 443.53 3/2 + 1036.73 lO0 1071.65 5 / 2 - 786.4 c 1322.42 5 / 2 - , 7 / 2 -
J. Honz6tko et al./Nuclear Physics A 645 (1999) 331-375 351
Table 3 - - continued
1 2 3 4 5 6
2129.60(3) 1 / 2 - , 3 / 2
2132.03(13) 3/2+,5/2,(7/2 +
2145.5(2) ( I / 2 + ) , 3 / 2
2150.1(1) 3/2,5/2 +
2176.0(2)* 1/2+,3/2
2181.93(6) 1/2+,3/2
2204.09(4) I / 2 - , 3 / 2
2220.17(15) 3/2 +
2226.18(5) 3/2 ~-)
2232.6(3)
2246.51(6) 1 / 2 - , 3 / 2 -
2251.14(8) 1/2+,3/2
2270.83(6) 1/2+,3/2
2292.9(1)
2094.09 100 35.49 3/2 + 1686.18 m <64 .0 443.53 3/2 + 1591.84 21.0 537.79 (1/2 + ) 1057.50 15.9 1071.65 5 / 2 - 1688.45 443.53 3/2 + 1668.6 c I00 463.34 5/24 1495.8 c 636.07 7/2 +
1461.36 m 671.42 5/2 + 1682.31 100 463.34 5/2 + 1473.7 c 671.42 5/2*
1686.18 n' 463.34 5/2 + 1611.56 84.2 537.79 (1/2 + ) 1078.24 I00 1071.65 5 / 2 -
2176.37 e 100 0.0 1/2 + 1732.87 m 443.53 3/2 + 1503.49 m < lO0 671.42 5/2 + 2182.41 e 40.6 0.0 I/24 2146.69 e 21.7 35.49 3/2 ¢ 1738.41 lO0 443.53 3/2 + 1643.80 81.1 537.79 ( 1/2 + ) 1510.43 C 671.42 5/2 ~ 1452.91" 729.22 3/2 + 1760.59 100 443.53 3/2 +
1132.37 "7 < 100 1071.65 5/2 881.74 42.5 1 3 2 2 . 4 2 5 / 2 - , 7 / 2 -
2184.7 s 35.49 3/2 + 1582.99 m 636.07 7/2 + 1578.04 m 642.21 7/2 ~ 1549.16 m 671.42 5/2 + 2190.71 58.6 35.49 3/24 1782.81 37.7 443.53 3/2 + 1763.35 26.2 463.34 5/2 + 1590.0 c 636.07 7/2 + 1554.84 100 671.42 5/2 + 1497.72 30.6 729.22 3/2 +
1160.78 m < 18 1066.42 3 /2+,5 /2 + 1788.02 lO0 443.53 3/2 +
1503.49 m < 40 729.22 3/2 + 2247.15 s 0.0 1/2 + 1802.1 c 443.53 3/2 +
1175.46 m 1071.65 5/2 1807.22 100 443.53 3/2 +
1713.43" 537.79 (1/2 + ) 1579.71 83.3 671.42 5/2 +
1522.38" < 66.7 729.22 3/2 + 1233.13" < 41.7 1017.71 1/2+,3/2,5/2,7/2 ~ 2270.49 s 50.0 0.0 1/2 + 2235.56 s 100 35.49 3/2 + 1732.87 m < 80 537.79 ( I / 2 + ) 1599.60 63.3 671.42 5/2 + 1541.37 18.8 729.22 3/24 1656.87 100 636.07 7/24 1274.60 21.8 1017.71 3 /2+ ,5 /2 ,7 /2 + 1049.35 50.0 1242 .94 1 /2+,3 /2 ,5 /2 +
352
Table 3--continued
J. Honz6tko et al./Nuclear Physics A 645 (1999) 331-375
1
2310.75( 10)*
2313.54(11)
2315.64(11)
2351.66(6)
2372.6(1)
2379.47(6)
2384.1(2)*
2410.1(1)
2415.6(1)
2438.7(2)
2466.59(7)
2 I /2 +, 3/2, 5/2 +
1/2+,3/2
3 / 2 -
( I / 2 + ) , 3 / 2
( 1 / 2 + , 3 / 2 , 5 / 2 + )
( 3 / 2 - )
3/2
1/2+,3/2
1/2+,3/2
( 1 / 2 + ) , 3 / 2
3 4 5 6 2310.6 e 100 0.0 1/2 + 2275.7 e 95 35.49 3/2 + 1847.3 c 463.34 5/2 +
1582.99 m < 170 729.22 3/2 + 1045.52 49 1265.16 3/2 + 2313.68 100 0.0 1/2 + 2278.17 19,8 35.49 3/2 + 1870.03 67,2 443.53 3/2 + 1584.60 46,8 729.22 3/2 + 1872.00 e 100 443.53 3/2 + 1852.23 c 463.34 5/2 + 1777.95 c 537.79 (1/2 + ) 1261.0 m < 150 1053.76 5/2 + 1244.12 c 1071.65 5 / 2 - 1182.65 74,6 1133.11 (5/2 + )
2316.21 s 58,1 35.49 3/2 +
1908.26 86.5 443.53 3/2 + 1888.41 m 463.34 5/2 + 1680.09 100 671.42 5/2 +
1621.59 "1 < 104 729.22 3/2 + 1298.4 c 1053.76 5/2 + 1140.4 c 1209.73 5 / 2 - , 7 / 2 + 1929.1 m 443.53 3/2 + 1910.50 463.34 5/2 + 1834.81 537.79 (1/2 + )
2380.00 s 0.0 1/2 + 1935.7 40.0 443.53 3/2 + 1916.0 ¢ 463.34 5/2 + 1841.51 59.8 537.79 ( 1/2 + )
1708.90 m < 69.8 671.42 5/2 + 1650.30 100 729.22 3/2 +
2348.17 e 35.49 3/2 + 1921.59 m 463.34 5/2 + 1713.43 m 671.42 5/2 + 1947.3 c 463.34 5/2 + 1338.1 m 1071.65 5 / 2 -
1087.36 m 1322.42 5 / 2 - , 7 / 2 - 2415.34 ~ 44.4 0.0 1/2 +
2380.00 m's 35.49 3/2 +
1744.05 100 671.42 5/2 + 1686.49 m 729.22 3/2 + 1096.06 33.3 1319.53 3 / 2 -
2402.90 s 100 35.49 3/2 + 1899.45 22.7 537.79 (1/2 + ) 1768.03 10.3 671.42 5/2 +
1709.99" < 36.7 729.22 3/2 + 2467.03 s 67.2 0.0 1/2 + 2430.44 ~ 70.4 35.49 3/2 + 2022.92 69.3 443.53 3/2 + 2002.63 60.3 463.34 5/2 + 1928.9 63 537.79 (1/2 + )
1795.12 100 671.42 5/2 + 1412.60 m < 59 1053.76 5/2 +
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 353
Table 3 - - continued
l 2 3 4 5 6
3/2 2495.4(1)
2504.2(2)* I /2+ ,3 /2
2521.4(1)* 3 / 2 -
2528.6(1)*
2550.14(4) ( 3 / 2 - )
2560.9(2)* 1/2,3/2
2568.0(1) 1/2+,3/2
2585.31(19) 1/2,3/2
2591.2(2)*
2607.12(15) 1 /2 - ,3 /2
2649.81(8) 3 / 2 -
2689.7(2)* 2705.9(1)* I /2,3/2
2729.64(12) 1/2,3/2
2460.77 s 100 35.49 3/2 + 2049.62 19.0 443.53 3/2 + 2032.13 42.8 463.34 5/2 + 1422.8 c 1071.65 5 / 2 - 2469.6 s 35.49 3/2 + 2060.67 100 443.53 3/2 +
2041.46 m < 100.0 463.34 5/2 + 2521.8 m's 0.0 1/2 + 2485.8 e 35.49 3/2 +
(2077.04)" 443.53 1/2' 1851.54 m 671.42 5/2 + 1857.71 89.8 671.42 5/24 1799.3 100 729.22 3/2 +
2550.78" 0.0 1/2 ~ 2514.62 89.9 35.49 3/2 ~ 2106.25 100 443.53 3/2 + 2086.99 92.0 463.34 5/2 + 2014.16 75.2 537.79 (1/2 ~ ) 1477.8 39.1 1071.65 5 / 2 -
2560.66 s 100 0.0 I /2 + 1832.17 70.0 729.22 3/2 +
2568.21 m < 82.4 0.0 1/2 + 2532.81 100 35.49 3/2 7
2124.66" < 54.2 443.53 3/2 ~ 2103.37 m < 50.0 463.34 5/2 + 1838.42 33.3 729.22 3/2 ~
1435.91 m < 20.8 1133.11 5/2 7 2550.78 m 35.49 3/2 + 2141.76 56.1 443.53 3/2 + 2122.4 20.8 463.34 5/2 +
2047.27 100 537.79 ( I / 2 + ) 2128.1 463.34 5/2 ~ 1950.2" 642.21 7/2 + 2607.01 I00 0.0 I/2 ~ 2571.92 57.7 35.49 3/2 + 1878.48 56.7 729.23 3/2 + 1535.02 58.7 1071.87 5 / 2 - 1288.3 c 1319.53 3 / 2 -
2649.90 c 0.0 I/2 + 2614.26 47.7 35.49 3/2 ~ 2204.84 27.8 443.53 3/2 + 2186.69 100 463.35 5/2 +
2124.66 m < 36.3 525.34 7 / 2 - 1921.59 m < 121 729.23 3/2 + 1584.60'" < 44.4 1 0 6 6 . 4 2 3 /2+,5 /2 ~ 1578.04 80.6 1071.87 5 / 2 - 1515.71 22.2 1133.11 (5/2) 7 1330.4 c 1319.53 3 /2 - 2018.25 100 671.43 5/2 + 2670.59 ~ 100 35.49 3/2 +
2730.55 m,s 0.0 1/2 + 2190.7" 537.79 (1/2 + ) 1595.7 c 1133.11 5/2 +
354 J. Honzdtko et aL /Nuclear Physics A 645 (1999) 331-375
Table 3 - - continued
1 2 3 4 5 6 2751.8" 1/2,3/2
2754.1(3)* 1/2,3/2 2770.71(10) 3 / 2 -
2775.8(1)* 1/2,3/2 2785.83(10) ( 1 / 2 - ) , 3 / 2
2801.9(2)* 1/2+,3/2
2813.9(2)* 1/2,3/2
2819.7(2)* 1 /2+,3 /2
2898.4(2)* 1/2+,3/2
2938.3(2)* 1/2,3/2
2951.94(10)* 1/2,3/2
2974.9(1) 1/2+,3/2
2990.7(2) 1/2+,3/2
3002.01(8) 1/2+,3/2
3021.6(1) 3/2
3072.3(1) 1/2+,3/2
2751.1 m's < 4 4 0.0 1/2 + 2716.33 s 100 35.49 3/2 + 2215.88 100 537.79 (1/2 + ) 2770.45 33.3 0.00 1/2 + 2735.48 50.0 35.49 3/2 +
2308.51 m 33.3 463.35 5/2 + 2233.01 m 26.6 537.79 (1/2 + ) 1698.54 100 1071.87 5 / 2 -
2333.01 m 100 443.53 3/2 + 2786.30 s 0.0 1/2 +
2751.12 s'm 35.49 3 /2+ 232t,6 c 463.35 5/2 +
1713.43 m 1071.65 5 / 2 - 2801.9 s 0.0 1/2 +
2338.2 463.35 5/2 + 2370.18 m 443.53 3/2 + 2351.75 m 463.35 5/2 + 2784.34 s 100 35.49 3/2 + 2355.65 88.9 463.35 5/2 + 2148,9 c 55.6 671.42 5/2 +
2898.00 s 100 0.0 1/2 + 2434.95 m < 50.0 463.35 5/2 + 2902.38 s 100 35.49 3/2 + 2492.29 m 443.53 3/2 +
2916.87 m'~ 35.49 5/2 + 1878.48 m 1071.65 5 / 2 - 2939.98 ~ 25.0 35.49 3/2 + 2510.92 100 463.35 5/2 + 2302.6 m < 72.2 671.42 5/2 + 2245.30 61.1 729.22 3/2 + 2990.02 s 48.3 0.0 1/2 +
2956.05 s'm 35.49 3/2 + 2547.2 25.0 443.53 3/2 +
2527,19 100 463.35 5/2 + 2317.9 37.5 671.42 5/2 + 2262.6 12.5 729.22 3/2 +
2539.40 29.4 463.35 5/2 + 2330,27 100 671.42 5/2 + 2273.36 70.6 729.22 3/2 + 3022.27 s 40.9 0.0 1/2 + 2986.37 ~ 81.8 35.49 3/2 + 2557.38 100 463.35 5/2 + 2483,79 27.3 537.78 1/2 + 2291,32 36.4 729.22 3/2 + 1949.3 c 1071.65 5 / 2 -
1699.87 m 1322.42 5 / 2 - , 7 / 2 - 3036.76 s 59.1 35.49 3/2 + 2400.47 100 671.42 5/2 + 1829.68 m 1242.94 1 /2+ ,3 /2 ,5 /2 +
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 355
Table 3 - - continued
l 3106.08(12)
3142.31(10)
3174.2(1)
3183.9(2)
3208.26(9)
3290.9(3)*
3430.1(I)
3532.7(3)
3554.2(3)
3563.6(2)*
6568.97(3)
2 1/2 +,3/2
1 / 2 - 3 / 2
1/2~-~,3/2
1/2,3/2
1/2,3/2
1/2,3/2
1/2-,3/2-
1/2,3/2
1/2+,3/2
1 /2 - , 3 /2
1/2 +
3 4 5 6 3106.41 m 0.0 1/2 + 2662.78 64.7 443.53 3/2 + 2644.59 100 463.35 5/2 +
2568.72 m 537.78 1/2 + 2434.95 m 671.42 5/2 +
3142.48 m.s 48.4 0.0 1/2 + 3106.41 m.s < 80.6 35.49 3/2 +
2699.01 83.9 443.53 5/2 + 2070.68 100 1071.65 5 / 2 -
3138.67 m 35.49 3/2 + 2730.55 m 443.53 5/2 + 2103.37 m 1071.65 5 / 2 - 3184.20 s 100 0.0 1/2 + 2740.78 85.3 443.53 3/2 + 2454.17 66.7 729.22 3/2 + 3207.8 100 0.00 1/2 +
3174.07 64.2 35.49 3/2 + 2763.4 c 443.53 3/2 +
1888.41 m < 107 1319.53 3 / 2 - 3291.8 s 100 0.0 3/2 + 1971.59 73.3 1319.53 3 / 2 - 3430.5 ~ 0.0 1/2 +
3394.48 m.s 35.49 3/2 + 3496.54 m,~ 35.49 3/2 +
3089.15 443.53 3/2 + 3554.28 s 100 0.0 I/2 + 3519.2 "-s 35.49 3 /2+ 3092.10 56.0 463.53 5/5 + 3564.9 s 0.0 I/2 +
2492.29 100 1071.65 5 / 2 - 6569.25 38.0 0.0 1/2 + 6533.74 76.4 35.49 3/2 + 6125.58 27.1 443.53 3/2 + 6030.96 7.3 537.79 (1/2 + ) 5839.80 42.1 729.22 3/2 + 5502.4 1.9 1066.42 3 /2+,5 /2 + 5325.9 1.7 1242.94 1 /2+ ,3 /2 ,5 /2 +
5303.89 3.2 1265.16 3/2 + 5249.40 86.5 1319.53 3 / 2 - 5039.53 3.3 1529.66 3/2 + 4981.70 5.3 1587.28 1/2 + 4916.42 2.1 1652.53 3/2 + 4898.62 1.6 1670.16 3/2 + 4869.82 0.5 1699.93 3 / 2 - 4855.54 5.2 1713.52 1/2 + 4809.32 1.6 1759.49 3 /2+,5 /2 + 4703.84 3.2 1865.12 (1/2) ,3/2 + 4669.97 1.8 1899.00 (3/2 + ) 4663.93 3.6 1904.90 (3/2 + ) 4612.23 I00 1956.74 3 / 2 - 4590.27 14.6 1978.76 1/2 ~ - ) , 3 / 2 ~-) 4559.65 41.3 2009.33 3 / 2 -
356 J. Honz6tko et al./Nuclear Physics A 645 (1999) 331-375
Table 3--continued
1 2 3 4 5 6 4519.87 0.8 2049.51 3/2 + 4508.14 5.3 2061.02 3/2 + 4492.27 5.9 2076.95 1/2- ,3/2 4460.44 15.8 2108.58 3 /2- 4439.48 11.7 2129.60 1/2- , 3/2 4393.1 0.9 2176.0" 1/2+,3/2 4387.33 1.4 2181.93 1/2+,3/2 4364.7 1.2 2204.1 1/2-,3/2 4348.8 2.0 2220.0 3/2 + 4343.04 14.5 2226.18 3/2 ~ - ) 4322.40 1.7 2246.51 1/2- , 3 /2- 4318.0 1.2 2251.1 1/2+,3/2 4297.9 2.1 2270.83 1/2+,3/2 4258.4 1.8 2310.8 1/2+,3/2 4253.77 5.4 2315.64 3/2- 4217.73 5.9 2351.66 (1/2 + ),3/2 4189.45 8.1 2379.47 (3 /2 - ) 4159.0 1.4 2410.1 3/2 4153.1 1.6 2415.6 1/2+,3/2 4130.2 1.1 2438.7 1/2+,3/2 4102.72 4.5 2466.59 (1/2+),3/2 4074.6 1.7 2495.4 3/2 4064.8 1.0 2504.2* 4018.97 10.9 2550.14 (3 / 2 - ) 4008.22 2.3 2560.73* 1/2,3/2 4001.12 9.8 2567.98 1/2+,3/2 3982.95 11.6 2585.31 I/2,3/2 3979.18 2.2 2591.2" 3961.57 7.5 2607.12 I/2,3/2 3919.33 20.5 2649.81 3/2- 3894.67 5.0 2674.30* 1/2,3/2 3879.01 3.0 2689.49* 3863.33 2.8 2705.9* I/2,3/2 3839.46 3.8 2729.64 1/2,3/2 3813.9 1.9 2754.1 3817.2 1.7 2751.9" 1/2,3/2 3798.26 9.6 2770.70 3/2- 3793.37 2.4 2775.8* 1/2,3/2 3782.98 10.4 2785.83 (1 /2- ) ,3 /2 3766.9 1.1 2801.9" 3755.1 1.7 2813.9" 1/2,3/2 3749.48 5.7 2819.7 1/2+,3/2 3670.7 1.9 2898.6* 1/2+,3/2 3630.2 1.9 2938.3* 1/2,3/2 3617.14 3.8 2951.9" 1/2,3/2 3594.2 1.6 2974.2 1/2+,3/2 3577.9 5.6 2990.6 1/2,3/2 3567.3 6.0 3001.9 1/2,3/2 3547.7 13.7 3021.6 3/2
3496.54 6.4 3072.3 1/2+,3/2 3463.0 14.5 3106.3 1/2+,3/2 3426.7 10.0 3142.6 1/2-,3/2
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 357
Table 3 - - continued
* Uncertain level. " Data taken from Ref.141].
3 4 5 6 3394.5 11.2 3174.5 1/2 ( - ),3/2 3385.0 5.7 3183.9 I/2,3/2 3360.8 12.8 3208.3 1/2,3/2 3311.9 3.0 3256.7* I/2,3/2 3278.4 6.8 3290.9* I/2,3/2 3219.0 7.9 3350.1 1/2,3/2
3138.67 m < 11.1 3430.3 I /2 - ,3 /2 - 3036.76 m < 5.2 3532.7 1/2,3/2 3014.40 6.6 3554.2 1/2+,3/2 3006.68 2.8 3563.6* 1/2-,3/2
t, The intensity has been corrected for contribution of strong line 602.7 keV in 124Te. " Observed only in coincidences. ,/ Possible doublet of 3/2 + and 9/2- states. e Placement on energy relation only. m Multiple placement. ' Sum-coincidence method.
Combined population-depopulation analysis in the thermal neutron capture together with
the high resolution (d,p) data are compatible only with the 5 /2 + assignment for a single
level but do not rule out 3 /2 + .
The 1066.42 keV level
Six depopulating y-rays to low-lying levels with a wide range of spins do not allow us
to distinguish between 3 /2 + and 5 /2 + possibilities. Nevertheless, two strong deexciting
transitions to both 1/2 + states, the ground state and the 537 keV level, give some
preference for the 3 /2 + assignment.
The 1071.65 keV level
This new level is established uniquely in the (n ,y) reaction via four deexciting tran-
sitions. Populating and depopulating transitions suggest unambiguously a 5 / 2 - charac-
teristic.
The 1092.4 keV level
This level we identified with the 1 = 2 level at 1089 keV reported by RCdland et
al. [9]. Three y-rays which depopulate the level at 1092 keV do not allow us to
distinguish between 3 /2 + and 5 /2 + assignments.
The 1133.11 keV level
This previously known l = 2 level is defined by seven depopulating transitions. Two
of them going to both low-lying 7 /2 + states give a preference for the 5 /2 + assignment.
358 J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
The 1209.73 keV level
This new level is established uniquely in the (n,y) reaction. Two depopulating and six populating transitions limit the spin-parities to 5 / 2 - and 7/2 + .
The 1242.94 and 1245.9 keV levels
We introduce two close-lying levels instead of the one previously known but differently
assigned in the (t,d) and (d,t) studies. The observation of a weak primary transition to
the first level and its deexciting mode restricts the spins to 1/2 +, 3/2, but it does not
contradict the choice of 5/2 + since the expected E2 strength of the primary transition does not exceed the recommended upper limit (RUL) according to Ref. [43 ]. The latter characteristic is more consistent with the Monte Carlo simulation of the level population.
Another level at 1245 keV is established only in coincidences. The deexcitation mode shows a tentative 5 /2 + assignment and at the same time argues strongly against the
choice of 1 / 2 - , 3 / 2 - . It is not clear which level could be related to that reported in the
(d,t) reaction. In our (3He,a) spectrum the corresponding peak has a complex structure with a centroid energy of 1237 keV.
The 1265.16 keV level
The observation of the primary transition to the previously known l = 2 state firmly determines it as the 3/2 + state. The 5/2 + possibility is very unlikely since in this case the estimated E2 strength exceeds the RUL for the E2 primary transitions by a factor of 2.
The 1314.63, 1319.53 and 1322.42 keV levels
A group of close-lying levels at these energies with different angular momenta of I = 0, 2 and 4 were observed in the previous studies. In the present work we observed the level
at 1315 keV most pronounced in the (3He,a) reaction which can be identified with the l = 4 state known [9] from pick-up reactions. The observation of a strong depopulating
transition from this level to the 5/2 + state at 671 keV in the (n,y) reaction favors a spin assignment of 7 /2 +. The (3He,a) peak with a centroid energy of 1315 keV is not a single peak. The low energy tail could be caused by the high-spin state at 1310 keV observed by Kerek et al. [5] in the (a ,3ny) reaction, but the high energy tail could be due to two states at 1319 and 1322 keV. The level at 1319 keV strongly populated in the (n,y) reaction by a primary transition together with eight depopulating transitions allowed us to assign unambiguously a 3 / 2 - characteristic. The third level of this group at 1322 keV is established only via depopulation to the low-lying 9 / 2 - state and to two 7 / 2 - states limiting spin parity to 5 / 2 - , 7 / 2 - . The 9/2 and 11/2- possibilities should be excluded due to their expected very weak population in thermal neutron capture. Our spin-parity assignments for the latter two levels are in disagreement with those given previously in Refs. [8,9].
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 359
The 1521.16 and 1529.71 keV levels
We introduce two levels instead of one 1 = 2 state previously known at 1530 keV.
Considering the primary transition to the level at 1529 keV and depopulating transitions
to the two 7 /2 + states the unambiguous assignment of this state is 3 /2 + . Another level
at 1521 keV is given only by one y-ray depopulating to the 5 /2 + state at 463 keV
which does not allow us to determine the spin value. The 5 /2 + assignment would be
slightly more preferential, since the energy centroid in the pick-up reactions is shifted
to the lower side and could be due to the hole nature of the d5/2 state at 1521 keV.
The 1580.8 and 1587.28 keV levels
Previous ambiguities of the mutually exclusive spin-parity assignments for the level at
1584 keV are resolved by introducing two levels. Our 1587 keV level could be identified
with the old l = 0 state. We propose another new level at 1581 keV seen as a weak
(d,p) peak and depopulated by only one transition to the 3 /2 + state which does not
allow us to choose definitely spin parity. In the (3He,a) spectrum we see one weak, a
broad peak consisting of the two states mentioned above. The high angular momentum
indicated previously [9] could be due to the level at 1570 keV reported by Kerek et
al. [5] in (c~,3ny) studies.
The 1643.3, 1652.53, 1661.5 and 1670.16 keV levels
Our data allow us to introduce two 3 /2 + levels at 1652 and 1670 keV both populated
by primary transitions and depopulated by nine and seven transitions, respectively. We do
not exclude the possibility of another close-lying state of high spin ( 9 / 2 - ) at 1652 keV deexciting to two 7 / 2 - states at 525 and 787 keV which could be associated with the
1 = 5 fragment of the complex peak in the (3He,a) spectrum reported in Ref. [9] .
Unfortunately, the situation becomes more complicated since in our a spectrum we
see two distinct peaks at 1643 and 1661 keV for which we are unable to observe
depopulating transitions. Also, it is not clear if our ce peak at 1643 keV is identical to
the (d,t) level at 1645 keV observed previously.
The 1699.93 keV level
There is an overwhelming preference for an l = 1 assignment for this level in
Ref. [41] . However, only a very weak primary transition was observed in thermal
capture. If this assignment is correct the depopulating transition to the 7 / 2 - state de-
fines unambiguously the characteristic 3 / 2 - .
The 1713.52 and 1732.2 keV levels
Two l = 0 and 1 = 4 states known from previous pick-up reactions can be identified with our states at 1713 and 1732 keV, respectively. Nevertheless, it is not clear why the strong (3He,re) peak at 1726 keV is shifted so much to the side of the state with a
lower angular momentum. We cannot rule out the possibility that the additional level at
360 J. Honzdtko et aL /Nuclear Physics A 645 (1999) 331-375
1715 keV weakly populated in the (d,p) reaction is a third state which could actually
be responsible to a great extent for the composition of this complex peak.
The 1766.45, 1771.16 and 1775.0 keV levels
We introduce a new level at 1766 keV on the basis of the five depopulating y-rays which restrict the spin-parity assignment to 3 / 2 - , 5 /2 or 7/2 +. A new level at 1771 keV
is defined by four secondary transitions which give an ambiguous spin assignment of 1/2 +, 3/2, 5/2, 7 /2 +. The third level of this group at 1775 keV is seen via only one
transition going to the 1/2 + state at 537 keV. The (d,t) peak at 1770 keV previously tentatively assigned to the l = 0-type actually consists of three levels. The angular distribution given in Ref. [9] can be understood as an interference of at least l = 0
and 1 = 3 waves. Thus the 5 / 2 - assignment for the state at 1766 keV would be more preferable. We maintain the 1/2 + characteristic for the state at 1775 keV.
The 1813.0, 1820.2 and 1832.3 keV levels
This group of levels at about 1820 keV with different angular momenta is known
from previous studies. In the present work we see at least three levels in this energy interval. The 1813 keV level depopulated to three low-lying levels with 1/2 +, 3/2 + and 5/2 + can be identified with the l = 2 (d,t) state previously reported at 1809 keV.
Similarly, the 1832 keV level can be identified with the l = 4 (d,t) state. The most pronounced (d,p) peak in this group at 1820 keV can only partly be identified with the old l = 3 state at 1816 keV. No y-rays were observed in thermal neutron capture which
could be associated with this level. Thus the tentative assignment of 5 / 2 - , 7 / 2 - could be given. There is some evidence for an additional level at 1824 keV weakly populated in the present (d,p) reaction. Perhaps the last two states together with that at 1832 keV
form the (3He,re) peak at 1826 keV.
The 1865.12 keV level
The observation of a primary and five secondary transitions allows us to propose the 1/2, 3/2 level at 1865 keV. If this is the same level known previously at 1857 keV, only
the spin assignment of 3/2 + is consistent with the l = 2 transition reported previously.
The 1899.0, 1904.9, 1911.1, 1918.55 and 1932.1 keV levels
Two levels at 1899 and 1905 keV are defined by primary transitions and each by at least six secondary transitions. Depopulating transitions to the 7/2 + states are of great
importance and establish a unique 3/2 + characteristic for both states. In any case this decision contradicts the previous l = 0 assignment. The 1911 keV level depopulated by four transitions could be related to the old l = 4 state reported by Rc~dland et al. [9]. The most intense component of this group in our (3He,or) spectrum agrees reasonably in energy with the (n,y) value. Two former 3/2 + states are weakly seen in the (d,p) reaction. The 1918 keV level observed in thermal neutron capture and weakly populated in (d,p) is identified with the known l = 2 (d,t) state at 1926 keV for which the most
J. Honzdtko et al./Nuclear Physic~ A 645 (1999) 331-375 361
probable spin-parities of 3 /2 + , 5 /2 + can be assigned. Another probable 5 / 2 - , 7 / 2 -
level at 1932 keV may be the same as the l = 3 state observed previously in the stripping reactions at 1925 keV.
The 1956.74 keV level
This level is populated in the (n,y) reaction by the most intense primary transition
and depopulated by 11 secondary transitions which provide an unambiguous 3 / 2 - assignment.
The 1968.9 keV level
This known l = 4 level depopulates by only one transition which does not allow us
to distinguish between 7 /2 + and 9 /2 + possibilities.
The 1978.76, 1982.9, and 1991.0 keV levels
The relatively strong primary transition to the level at 1978 keV suggests a 1/2, 3 /2
assignment and gives some preference to the negative-parity assignment. The 1 = 3 state
at 1978 keV known from the preceding (d,p) and (t,d) studies can be related to our
(d,p) state at 1982 keV since it has a significant intensity in this energy interval. Due to only one depopulating transition from this level to a 3 /2 + state the most probable
spin-parity assignment is 5 / 2 - . The 1991 keV level can be identified with the old I = 0 (d,t) state known at 1985 keV.
The 1995.0, 2009.33 and 2020.44 keV levels
The observation of a strong primary transition to the level at 2009 keV together with
the deexcitation mode strongly suggest a 3 / 2 - assignment which is in accordance with
the 1 -- 1 transition observed in previous stripping reactions. On the other hand, the an-
gular distribution in the previous (d,t) studies permits the 1 = 1 + 5 type. The observation
of a new level at 1995 keV in our (d,p) spectrum as well as in coincidences removes
this inconsistency. Three depopulating transitions are consistent with the plausible 9 / 2 - assignment. The 2007 keV peak in our (3He,a) spectrum shows a doublet structure.
The experimental cross-section ratio of our measurement at 32 MeV to the previous one
of Rodland et al. [9] at 24 MeV is about 0.81, indicating a lower angular momentum
lor this complex peak. We also introduce a new level at 2020 keV depopulated by three
3,-rays to the 3 /2 ÷, 5 /2 + and 7 /2 + states which restrict possible spin-parity assignment
to 3/2 ~ , 5/2 , 7 /2 +.
The 2049.51 keV level
The observation of a primary transition and six depopulating transitions firmly indi-
cates the 3 /2 + characteristic. This is, however, inconsistent with all previous data which
suggest an 1 = 1-type transition. Nevertheless, the intensity ratio of 15 ° to 30 ° in our (d,p) spectra permits the 1 = 2 type instead of 1 = 1. The discrepancy might be resolved
362 J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
by introducing a new close-lying level at 2047.4 keV depopulated by only one very strong transition to the 5 / 2 - level at 1071 keV.
The 2061.02 and 2068.7 keV levels
The 2061 keV level is unambiguously assigned as the 3/2 + state because of the population by a primary transition and the depopulation to the 7/2 + level at 636 keV. We introduce the tentative level at 2068 keV on the basis of only two transitions going to the 3/2 + and 5/2 + levels which restrict the possible spin-parity assignment to <~ 7/2.
The 2076.95 and 2079.5 keV levels
The new level at 2077 keV is based on a primary transition and on three depopulating transitions which restrict the spin-parities to 1 /2- , 3/2. The new (d,p) level at 2079 keV could be associated with the 2082 keV (3He,a) peak which in previous studies has been assigned as the l = 4 level. No y-rays were observed depopulating this level which gives indirect evidence for a high-spin state.
The 2108.58, 2112.5 and 2126.8 keV levels
Unresolved doublets or triplets with the l = 1 + 3 transfer were previously observed in the stripping reactions at 2105 keV. We suggest a 2109 keV level populated by an intense primary transition and depopulated by five transitions which restrict the spin- parity assignment to 3 / 2 - , 1 /2- . We established two states at 2112 and 2126 keV which are the strongest peaks in our (d,p) spectra excluding the three corresponding to the lowest Sl/2, d3/2, hll/2 excitations. The angular momenta for both levels (from the ratio 15°/30 °) must be comparatively high, l >/ 3, indicating a possible h shell structure. The (3He,a) peak at 2105 keV could not be interpreted simply since it is probably composed by two or more transitions.
The 2129.6 and 2132.0 keV levels
Two new levels at 2130 and 2132 keV were observed only in the (n,T) reaction. The former is populated by a primary transition and depopulated by four transitions which indicate spin-parity 1 /2 - , 3/2. The latter is depopulated by four transitions without any indication of a primary population. This implies several possible spin-parities of 3/2 +, 5/2, (7/2+).
The 2145.5, 2150.1 and 2159.9 keV levels
Two new levels at 2145 and 2150 keV were established in the (n,T) reaction by observing the secondary transitions. There is weak feeding of the 2145 keV level by primary transitions. We propose the spin assignment (1 /2) +, 3/2 for the first level and 3/2, 5 /2 + for the second. The newly observed (3He,~r) level at 2160 keV can be related to the previous (d,t) state at 2157 keV.
J. Honzdt~ et al./Nuclear Physics A 645 (1999) 331-375 363
The 2175.0, 2181.93, 2187.7 and 2204.09 keV levels
Two levels at 2175 and 2182 keV are observed in the (n,y) reaction. Both levels are equally populated by weak primary transitions and depopulated to the 3/2 + and 5/2 + states. This implies the same spin-parity assignments of 1/2 +, 3/2. No evidence was observed for the population of these levels in our (d,p) spectra. Also, it is not clear which state of this doublet was observed previously in (d,t) studies where this level was tentatively assigned as the 1/2 + state. A new level populated by a weak primary
transition is observed at 2204 keV. Contrary to the levels mentioned above, in this case
two depopulating transitions going to the 5 / 2 - states permit 1 /2 - , 3/2 assignments. The present (d,p) and (3He,or) studies indicate the existence of an additional level at
2188 keV which was not found in thermal capture. Obviously, the angular momentum
of this level is high enough and consistent with the tentative value l = 4 reported in Ref. [9]. We also cannot exclude the possibility that the latter is not the same as seen in the (d,p) reaction considering its moderately strong population.
The 2220.17, 2226.18 and 2232.6 keV levels
The 2220 keV level populated by a primary transition and depopulated to the two 7/2 + states can be firmly assigned as the 3/2 + state which is in agreement with the
l = 2 assignment of this level in the previous (d,t) studies. Similar arguments applied to the level at 2226 keV establish a spin value of 3/2. The sufficiently intense primary
transition to this level gives an additional argument for the negative parity. The new level at 2232 keV is less certain as only two secondary y-rays were observed to depopulate
it.
The 2246.51, 2251.1 and 2270.83 keV levels
The levels of this group are equally populated by primary transitions and depopulated in a similar way to the 3/2 + and 5/2 + states. They are all 1/2 or 3/2 states. A
comparison of the levels of this energy group reveals some inconsistencies. The 2251 keV
level seen in our (d,p) spectrum is probably the same as that previously known from the stripping reaction with l = l at 2244 keV, since no other structures were observed in
this interval in our high resolution spectra. On the other hand, there is no evidence for negative parity, inspecting the depopulation of this state in thermal capture. However, the moderately intense transition from the 2246 keV level to the 5 / 2 - 1071 keV level might be MI determining negative parity for this state.
The 2313.54, 2315.64 and tentative 2310.7 keV levels
The level at 2315 keV is defined by the population by a moderately intense primary transition. However, there are some inconsistencies in energy of about 2 keV of the depopulating transitions, namely to the ground, 35 keV and 443 keV states which could be overcome if we introduce two closely lying levels at 2313 and 2315 keV both populated by primary transitions with an intensity ratio of about l:5. The deexcitation mode for the former levels suggests the 1/2 +, 3/2 assignment. For the latter the 3/2
364 J. Honzdtla~ et al./Nuclear Physics A 645 (1999) 331-375
characteristic is more preferable because of the depopulating transitions to the 5/2 + and 5 / 2 - states. It should be noted that, in the present measurements, agreement between the (n,y) and (d,p) reactions may be observed only for the 2315 keV level. Thus, only
the negative parity for this state is consistent with the l = 1 assignment established from the old (d,p) and (t,d) studies. Five plausible depopulating transitions (two introduced only due to the good energy combination) and the very weak feeding by a primary transition determine the level at 2311 keV only tentatively and limit the spin-parity
assignment to 1/2 +, 3/2, 5 /2 +.
O t h e r s ta tes
At higher energies nearly all observed levels are new. Only a few of them have been observed in previous stripping reactions. Due to the high level density it is often difficult
to relate the levels with others observed in different reactions. The correspondence in energy between the (d,p) levels and the (3He,a) peaks could be rather accidental
since the latter are composed in most cases of several states. Also, agreement between
the (d,p) and (n,y) levels is rarely observed. Therefore, the available spectroscopic information for this energy range is comparatively scarce. On the basis of the observation
of primary y transitions from the capture state l / 2 + spin value for most observed levels
have been restricted to 1/2, 3/2. In some cases additional spin-parity restrictions follow
from deexcitation of these levels to 5/2 + or 5 / 2 - states. A level has been observed at 2649.81 keV with an unambiguously determined spin-parity assignment inferred on
the basis of decays from the capture state and the subsequent deexcitation mode. Many unresolved multiplets in the y-ray spectrum could be partly resolved by the two-step
cascades technique [44]. The statistical features of these cascades will be discussed in a subsequent article.
4. Discussion
4.1. G e n e r a l cons ide r a t i ons
According to the simple shell model the N = 50-824 neutron shell contains the lg7/2,
2d5/2, 3S1/2, I h 11/2 and 2d3/2 orbits which play an active role in excitations of the 125Te nucleus. The large number of states observed in the present work indicates a strong fragmentation of the individual subshell strength due to the interaction of nucleons on valence orbits as well as on inner core orbits. We also observed many transfer reactions to the 2f7/2, 3p3/2, lh9/2 and 3pl/2 orbits above the N = 82 neutron shell. The usual DWBA technique allows us to obtain the individual shell-model and sum-rule strengths.
The extraction of transition strengths for the various transferred orbital angular mo- menta I is available in the present work up to an excitation energy of about 2.3 MeV. The summed spectroscopic strengths observed in the stripping and pick-up reactions together with the degree of "emptiness" (U z) and "fullness" (V 2) of the neutron subshells are listed in Table 4.
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
Table 4 Experimental values of the summed spectroscopic strengths of the neutron subshells in J25Te
365
Neutron Stripping Pick-up
orbit 2.: (2J + 1)$1 U z 2" S l V 2 U 2 q.- V 2
3su2 0.59 0.29 1.65 0.83 I. 12 3p3/2 0.74 2d3/2 1.71 0.43 3.86 0.96 1.39 2d5/2 0.54 0.09 4.02 0.67 0.76 2f7/2 1.42 0.18 0.26 0.03 0.21 2f5/2 0.16 Ig7/2 0.72 0.09 8.64 1.08 1.17 lg9/2 5.1 (2.8) a 0.51 Ihl I/2 2.12 0.18 6.2 0.52 0.70 I h9/2 ( 2.45 ) ( 0.1 )
aFor the discrete part.
As can be seen the s u m U 2 + V 2 satisfies within the usual experimental uncertainties
the normalization condition for the 3sl/2 and lg7/2 orbits. A slight excess in population
is observed for the 2d3/2 orbit. On the other hand, the slight deficiency of population of the same order for the 2d5/2 orbit can be understood. There are many unassigned states below and above the excitation energy of 2 MeV which could bring the "missing"
2d5/2 strength. The lhll/2 strength is mainly concentrated in only one state at 145 keV. No other 11 /2- states could be firmly identified, although there is some indication for high l transitions at 2391, 2426, 2450, 2557 and 2680 keV. However, these states could
alternatively be assigned to the lh9/2 or the lg9/2 orbits since they both equally appear in the (d,p) as well as in the (3He,ce) reaction. The state at 2127 keV can be attributed
to the 1h9/2 orbit with (2J + 1)St = 2.45, since the complete lack of this state in the (3He,~e) reaction strongly supports the particle-like origin of this state.
Turning now to the l = 1 and 3 transitions we can state that the corresponding
strengths are strongly fragmented over a wide energy range with a centroid far above 3 MeV. The large number of I = 1 transitions in the (d,p) spectra above 2.4 MeV could not be assigned unambiguously. Due to the large level density it is dangerous to relate the (d,p) and (n,y) states using only their identical energies. Most of the l = 3 strength listed in Table 4 is related to the states at 786 and 2112 keV which could be attributed
to the 2f7/2 orbit. Special attention should be paid to the 1 = 4 strength. According to the previous
(3He,a) studies by Rcdland et al. [9] the unresolved part of the a-spectra between 2.25 and 3.6 MeV is consistent with l = 4 or 5 transitions. The better resolution of the present work allows us to partly resolve this energy interval into discrete and continuous parts. The numerical evaluation of these parts in terms of spectroscopic strengths comprises knowledge of the background level versus the excitation energy. Because the energy range in our measurements is limited to about 4.6 MeV the usual procedure which smoothly connects the flat part at high excitation energy to the minima
366 J. Honz6tko et al./Nuclear Physics A 645 (1999) 331-375
of the cross sections in the lower discrete energy region (e.g., 2 MeV) is not available. Our assumption about the background is based on data for a similar reaction with a 124Te target reported by Gales et al. [45], although some uncertainties remain due
to the different energies of the 3He beams in both reactions. Accounting for these limitations the total integrated spectroscopic strength of the gross structure in the range
2.3-4.6 MeV is about 5, if we assume the l = 4 pick-up from the lg9/2 orbit. The deduced spectroscopic strength is comparable to those obtained for the deep-lying lg9/2
hole orbit in Te and Sn isotopes (A >/ 120) [45-48]. It should be emphasized that some states even at low energies, namely 1071, 1210,
1322 keV, etc., are not populated by any stripping or pick-up process. These states seem
to be related to collective excitations.
5. IBFM description of states in 125Te
The success of the IBFM model applied to the Xe and Ba region [49,50] allows us
to extend this description to Te nuclei. The IBFM Hamiltonian is written as a sum of boson and fermion parts, as well as a boson-fermion interaction containing a monopole- monopole, a quadrupole-quadrupole and an exchange term, respectively [52]; we use the version of this model which does not distinguish between neutrons and protons (IBFM-1). 125Te is described as a boson 126Te core to which one couples a fermion
hole allowed to occupy different spherical shell model orbitals. The energy ratio of the 4 + state to the 21 + state is nearly 2.0 in neighboring 124'126Te
nuclei, showing a character close to the U(5) limit (purely vibrational). However, the
2 + state, expected at the same ratio, actually lies at a higher energy, indicating some departure from this limit. Also, the nonzero branching ratio
B(E2;2 + --~ 0 + ) / B ( E 2 ; 2 + --+ 2 +) ----- 0.004
shows no pure vibrational limit. Additionally, it seems that some aspects of the nuclear
structure of even Te isotopes might be better described within the quasiparticle phonon model, especially for those isotopes with larger neutron numbers [20,22,23]. Despite this discussion, we can use in our description of the 124'126Te core IBM parameters
similar to those of the intermediate case relevant to the Xe-Ba region: EPS=0.7 MeV, PAIR=0.02 MeV, ELL=0.01 MeV and X = -0 .8 (in the notation used in the input of the IBM code PHINT [51]) .
Since we observe experimentally neutron pick-up from orbitals below N = 50, as well as stripping to orbitals above N = 82, in the present multishell calculations we had to include more orbitals than only those from the "valence" shell 50-82. Thus, in addition to the orbitals 2d5/2, lg7/2, 2d3/2, 3sl/2 (for positive-parity levels) and lhll/2 (for negative parities), whose single particle energies were chosen according to the prescription of Reehal and Sorensen [53], we have added the orbitals 1t"5/2, 2p3/2, 2pl/2 and lg9/2 (below N = 50) and 2f7/2, 3p3/2, lh9/2 and 3pl/2 (above N = 82), at relative energy spacings as provided by the universal Woods-Saxon potential of Nazarewicz et al. [54].
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375 367
For all these orbitals, we performed a BCS calculation, which provided the quasiparticle
energies and shell occupancies required as input for the IBFM calculations. For the
positive-parity levels we employed the four positive-parity valence orbitals specified above and, in a subsequent calculation, we kept the same model parameters and added the distant g9/2 orbital. For the negative-parity levels, since the existing code [55] allows
only five orbitals, we made separate calculations as follows: one with lh 11/2 to which we
added 2f7/2, 1f5/2, 2p3/2 and 2pl/2 orbitals (suitable for the calculation of the stripping strengths), and one with lhll/2 plus 2f7/2, 3p3/2, 1h9/2 and 3pl/2 orbitals (suitable for the calculation of the pick-up strengths). Actually, the addition of the orbitals "distant"
with respect to the valence orbitals has little effect on the position of the low-lying levels; it may affect somewhat the details of the fragmentation of the different orbitals, but not the general features of the strength distributions.
The boson-fermion interaction strength parameters, adjusted such as to provide a good description of the low-lying levels, could be taken the same for both the positive
and negative-parity levels: Ao = -0.21 MeV, /'0 = 0.36 MeV and A0 = 0.98 MeV. The
x-value in the boson quadrupole operator was chosen equal to the value used in the IBM description of the core: X = -0 .8 .
The effective boson and fermion charges and g-factors used in the calculation of the electromagnetic M1 and E2 transitions were as follows: eB = 0.09 eb, eF = --0.1 eb,
gl = 0, gs = -1 .148 tZN, ga = 0.21 /ZN. The boson effective charge e~ and the g-factor g,l were fixed by the B(E2; 2+--+0 +) value and magnetic moment of the 2 + state of the core, respectively; the fermion charge eF was chosen equal to eB but of opposite sign since the odd particle is a hole; finally, the gs value of the free neutron was quenched
by factor 0.4 as in the Ba case [50]. We also calculated the spectroscopic factors for the one nucleon transfer reactions.
The coupling scheme follows the hole- or particle-like character of the odd particle. The initial nucleus 126Te for the pick-up reaction has N = 5 bosons, whereas for the stripping reaction it is 12aTe and has N = 6 bosons.
The transfer operators for pick-up (stripping) are those defined in Ref. [56] as the sum of two terms T~ t = At ÷ B~. The first term describes single particle transfer where ./ ./ both the even and odd nucleus have N bosons
At [u"a~-~-~ V-~N~V/ 10 ~-~ ] / ' = . 2j + 1 1~J'J(K~)-lst(da~')(i) K~, .I
and the second term the case in which the odd nucleus has N and the even nucleus N + 1 bosons
.,:[. ]/ .1 "l " + uj 2j + 1 ~J'J(Kl3)-l(d'f~')(J) KI~" j
The summation is taken over all considered single-particle levels and the coefficients in the sums are determined according to the prescription of a semi-microscopic boson-
fermion mapping procedure [57 ].
368 J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
2o0op
~.150( >.. L3
L~J Z ~.~100C Z 0 - - 5 3
<
E-- 500 35, L) X
52 7,9__
Positive-parity
_ - - - - _ = - _
_ : - - _
-- ~ = -:. _
- z -
IBFM s~2 ~ ,
(d,t) ~1'0:
79-
5r~_': 15-
IBFM
(d,p)
3 1 - - ,ttp ~ e~. ~eo.exp exp t~o. , ~ t~o ~/'2" 3t'2" 3/~-7~ 5/'2* 7/2'
2 1 05 1.0 1.5 20 S~, (2J+ 1 )Sap Sat (2J+ 1)Sap
2000
1500
1000
500
Fig. 4. Comparison of the experimental level energies and spectroscopic factors with theoretical predictions for positive-parity states in ~25Te (center). The levels are arranged into several spin bins excluding those experimental levels with ambiguous spin assignments which are given in a separate 3 / 2 + - 7 / 2 + column. When unambiguous, the correspondence between the two sets of levels is indicated by a broken line. On the left-hand side the experimental spectroscopic factors are shown for both stripping (right) and pick-up (left) reactions. All spin values are multiplied by 2. The right-hand side gives the calculated IBFM values for S-factors. The spin values are additionally labeled by the order in which they appear in the calculations.
5.1. Posit ive-parity states
The calculated IBFM energy spectrum of 125Te is shown in Fig. 4 in comparison
with the experimental data. Experimentally, above the lowest doublet 1/2 +, 3/2 + there is a doublet 3/2 +, 5 /2 + which is reproduced very well in the IBFM calculation. These
levels show a one-to-one relation between the theoretical and experimental spectroscopic factors, indicating coupling of the ground 3s~/2 state to the 2 + boson core state. In the next higher-lying group a quadruplet of experimental levels 1/2 +, 7/2 +, 5/22 +, 3/2 + arising from the coupling of the same 2 + boson state to the 2d3/2 state corresponds to
the quadruplet of calculated levels. The spectroscopic factors for the first and two last members are well reproduced by the calculations. As for the 7/2 + state experimentally,
there are two closely-spaced 7/2 + states at 636 and 642 keV with almost equal S-factors. The two corresponding calculated 7/2 + states are moved apart by 100 keV. For this reason the calculated spectroscopic factor ascribing the lgT/2 state is mostly concentrated in the higher member. However, the calculated summed S-value over both lowest 7/2 + states is in very good agreement with experiment for the narrow experimental doublet.
The predictive power of the IBFM wave functions employed in the calculation can be seen in Table 5, where the E2 and M1 transition rates and branchings are tabulated for the group of levels mentioned above. Experimentally, the first and second 5/2 + states at 463 and 671 keV have comparable E2 branching to both low-lying 1/2 + and 3/2 + states, suggesting nearly equal wave functions; according to calculations the 5/2 + state
J. Honzdtko et aL/Nuclear Physics A 645 (1999) 331-375
Table 5
M1 and E2 transitions between low-lying states of positive parity in ~25Te
369
El Transition E~, B(MI)(#2N ) B(E2) (e2b 2 ) Branching
(keV) Ji Jf (keV) Theor. Exp. [41] Theor. Exp. 141 I Theor. Exp.
35,49 3/21 1/21 35.49 0.523x10 -°3 0.398x10 (n 0.721xl0 -°2 0.378×10 -° l 100 100 44353 3/22 1/2 t 443.53 0.625X10 -°3 0.232x10 -°2 0.352x10 -°1 0.89x10 -m 100 100
3/2 i 408.04 0.584x10 -°3 0.351x10 -°2 0.369x10 -~2 0.679x10 -m 14.5 58.0 463.34 5/21 1/21 463.34 0.147x10 -m 0.516x10 -m 88.7 37.0
3/21 427.85 0,912x10 -I]4 0.215x10 -°1 0.238x10 -m 0.486x10 -m 100 100 3/22 1 9 . 9 0.450x 10 -m 0.682x 10 .o3 0.1 0.1
537.79 1/22 1/21 537.79 0.254x10 -°1 0.000x10 +lx~ 100 100 3/21 502.30 0.131xl0 -°2 0.335xl0 -° l 23.3 57.0 3/22 94.26 0.271 x 10 -°3 0.242x I0 - °2 ,~0 5/2 j 74.45 0.455 x 10 -o2 ~,~0
636.07 7/2 i 3/21 600.58 0.394x10 -m O. 17gxlO -m 100 I00 3/22 192.54 0.944x 10 -(13 ~0 5/21 172.7 0.194x10 -°5 0.216x10 -°2 0.635x10 -~)2 0.15x10 -°5 ~0 I,I
642.21 7/22 3/21 606.7 0.279xl0 -°2 0 .1xl0 -°2 100 100 3/22 198.6 0.429xl0 -°3 0.37x10 -°3 0.1 0.27 5/21 178.8 0.907x 10 _03 0.626x 10 -°4 0.124x 10 -°2 3.3 0.57 7/21 6.14 0.179x 10 -°2 0.260x 10 -°1 ~0
671.43 5/22 1/21 671.43 0.269xl0 -m 0.438x10 -m 87.4 16.3 3/2j 635.91 0,618x10 -°2 0.922x10 -m 0.184x10 -m 0.36xl0 -m 100 100 3/22 227.91 0.648xl0 -°1 0.278x10 -°1 0.926x10 -°3 26.1 1.2 5/2i 208.09 0.358x10 -°1 0.673x10 -m 0.110x10 -°3 0.22xl0 -° l 11.0 2.1 1/22 133.6 0.814x 10 .o2 ~0 7/21 35.3 0.105x 10 -(12 0.194x 10 -113 ,-,~0 7/22 29.2 0.202x 10 -o4 0.367x 10 -o3 ~0
729.22 3/23 1/21 729.20 0.171x10 -°2 0.150x10 -°2 0.150x10 -°2 40.8 27.3 3/21 693.72 0,159x10 -°2 0.238x10 -°2 0.143x10 -° l 100 100 3/22 285.57 0.786x10 -°2 0.312x10 -°2 0.940x10 -112 9.2 8.3 5/21 265,9 0.993x 10 -°2 0,579x 10 -°2 9 1/22 191,43 0.183x10 -°2 0.326x10 -112 0,509x10 -°2 0.7 2.5 7/21 93,1 0,493 x 10 .o2 ~0 7/22 87.0 0,136x 10 -°1 ~0 5/22 57.8 0.630x 10 -o2 0,488x 10 -o2 0.1
is 32% sl/2 + 56% d3/2 + 4% d5/2 and the 5 /2 + is 48% S1/2 -~-34% d3/2 + 15% ds/2. On the other hand, the first two experimental 7 /2 + states at 636 and 642 keV demonstrate quite different E2 branchings to the two lowest 3 /2 + states. The calculated structures 72% d3/2 + 26% g7/2 for the 7 /2 + state, but 10% d3/2 + 88% g7/2 ['or the 7/2+, again nicely reproduce the experimental features. The significantly larger d3/2 component in the lower state gives an absolute E2 rate as much as one order of magnitude larger than for the upper state, being dominated by the g7/2 configuration.
Further experimental high-lying levels separated by a small gap of about 320 keV could be attributed to the next 2d5/2 and lg7/2 orbits. Experimentally, the wide energy distribution of the 5 /2 + and 7 /2 + levels up to 2.3 MeV is caused by the strong fragmentation of these hole-like structures. In contrast to the more or less smooth and
370 J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
Table 6 Calculated summed spectroscopic strengths of the main N = 82 neutron subshells in 125Te
Reaction Neutron orbit
3sl/2 2d3/2 2d5/2 1g7/2 lhl 1/2
Stripping 0.66 2.49 0.19 0.49 5.09 Pick-up 1.32 1.47 4.37 7.41 6.81
widely spread experimental pick-up strengths, the calculated ones still appear to remain in only a few states showing much less smearing of strengths. Thus a connection between experimental and calculated spectra could only be tentative using in each case
the largest S-factors. The largest experimental 2d5/2 strength is distributed among the
three states at 1054, 1133 and 1436 keV, yielding the value S = 2.33. Conversely, the corresponding calculated pick-up strength of S = 2.56 is concentrated in only one 5/2 + state at 1122 keV. The nearest calculated 5/2~ state gives only S = 0.14. At higher
energies the few calculated states 5 /2+ at 1860 keV, 5/2+2 at 2008 keV and 5/21+5 at 2135 keV have sizeable pick-up strengths of S = 0.27, 0.51 and 0.30, respectively.
The same is true for the lg7/2 strength, as can be seen in Fig. 4(right). In calculations the 7/2 + state at 831 keV brings the main part of the lgT/2 strength which may be compared with the experimental position at 642 keV. Coupling of the same lgT/2 to the 2j + boson core leads to the 11/2 + state at 1321 keV, in which this structure amounts
to 72%. Experimentally, the corresponding state was observed at 1191 keV. Above the
calculated 7/2 + state appear six additional calculated 7/2 + states with sizable pick-up strengths which could be related to the experimental states at 1149, 1314, 1357, 1732,
1832 and 1969 keV. As mentioned in Section 4.1 the continuous part of the a-spectrum above 2.3 MeV
can be attributed to the excitation of the deep hole lg9/2 orbit. We compare these experimental results with the IBFM calculations in which the distant g9/2 orbital has been
added to the four positive-parity orbitals from the 50-82 shell. The calculated g9/2 pick- up strength is, as expected, widely distributed in the energy range 2 to 8 MeV. However,
among 90 calculated states in this energy interval only two states at 5.17 and 5.96 concentrate 74% of the whole lg9/2 strength, and only 3.3% is situated below 5 MeV, therefore we see much less smearing of the strength than observed experimentally. Moreover, contrary to the present IBFM or previous QPM calculations [58], no two pronounced peaks are observed [45] inside the giant resonance-like structure. It should be emphasized, however, that our present estimation of the Ig9/2 strength distribution is based entirely on model parameters which were essentially determined by comparison with the low-excitation energy region of the spectrum. A real study of the deep hole states with the IBFM is in itself an interesting project.
At the same time, it should be noted that the calculated density of the positive- parity states below 2.3 MeV is about the same as observed experimentally. Also, the IBFM summed spectroscopic strengths given in Table 6 are in good agreement with the
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
experimental values of Table 4.
371
5.2. Negative-parity states
The family of negative-parity states is of considerable interest. While the high-spin branch ( J >/ 11/2) can be understood as arising from the coupling of the hll/2 neutron orbit to the even-even core states the low-spin levels observed below 1.5 MeV cannot correspond to the coupling of positive-parity states discussed above with negative-parity core states, since the latter only occur above 1.5 MeV. Similarly, they are too low in energy to contain significant amplitudes of the negative-parity states from the next N = 82-126 shell. Thus, from general considerations they must be predominantly states constructed by the coupling of the valence hi ~/2 neutron to the low-lying core excitations. The short scope of this "antialigned" member (the expression "antialigned" means that the coupling of the quasiparticle to the core states gives a spin smaller than that of the concerned quasiparticle, independent of the applied model) of the hit/2 family relevant to the y-deexcitation modes has already been reported in Ref. [26].
The previous IBFM description of high-spin multiplets of the h11/2 neutron quasi- particle, in general may be expected to be suitable also for the low-spin members. Attempting to identify the calculated levels with the experimental levels in as much detail as possible we have included in the actual calculations in addition to the 1h1~/2
orbit also the next 2f7/2, 3p3/2, 1h9/2 and 3pl/2 (N = 82-126) orbits. In calculations, especially of the pick-up S-factors, the deep-lying lf5/2 and 2pl/2 (N = 28-50) orbits were also taken into account. The calculations using practically the same set of model parameters as for the positive-parity states provide an essentially correct description of
the high- and low-spin states. Fig. 5 shows a comparison between predicted and measured spectra and gives the true
notation of calculated (right) and experimental (left) S-factors. The first few calculated levels of each spin value 9/21, 7/21, 5/21 and 3/21 easily follow the experimental levels and can be interpreted as members of the lowest multiplets formed by the coupling of the hl,/2 quasiparticle to the 0 +, 2 + and 4 + core states. Also, for the second 5 / 2 - , 3 / 2 - experimental levels the corresponding theoretical counterparts could easily be found.
The calculated 1/2~- member with the main components 95% lh11/2 + 4.6% 2f7/2 is
predicted at 1501 keV above the 11/2~- state. It is hard to associate this state with experimental levels. The lowest experimental 1/2- counterpart could be at 1978 keV, but it seems to be too far in energy. Above this group the further levels begin to have progressively more than one quasiparticle and one core state in their structure. Experience shows that the stripping and pick-up strengths for all members of the hi J/2 family are one to two orders of magnitude smaller than for the parent 11/2]- state. This feature is quite well reproduced by the calculations. Above the 11/2~- state and below 2 MeV excitation about eight additional 11/2- and six 9 / 2 - states are predicted by the IBFM calculations. This excess of predicted states is partly supported via the (cr,2ny) reaction [59] in the neighboring Xe isotopes with N = 71,73. Unfortunately, for all these states the S-factors are predicted to be almost zero and could not be
372 J . Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
2 0 0 0
.{ ~ 1 5 0 0
lOOO
~J
5 0 0 -
~ 5 ~ . . . . ' 3
> 7 > 7
~ 3
EXPERIMENT
3
~ 7
l o 3 . . . . . ib = . . . . . i 6 ' . . . . i0 ° (2J+l)Sdp
Negative-parity - - 3 5,7 - - - - 3 - - exp
1 , 3 ~ 3 _ _
" 1 4 ~ - - ( 5 ) , 7 - - G , 1 1 - - l ) ,&~- - 3 _ _ 1 ,~3 5 - - 9 - -
7 ~ - - 5 , 7 - - - - ~ 1,_. ~ - - 5 , 7 - - - - - - ---'T5
_ _ , ° _ ~ ,
- - 3 5 , 7 _ _ s,7-- ~ s
lheol ........ ' ........ ' ........ ' '
I
IBFM
- - ~ - ~ 9 3 - - 31
1 5 113
9, z 112 • " ~ ~s - - ~ ,
7
exp. theo. exp theo ~1 - - - - '111
112", 312" 5 i~ , 71~ 9/2", ~11/2"
10" 10" 50 3 10 2 5 0 500 1
(2J+l)Sd,
-2000
"1500
1000
500
Fig. 5. Same as Fig. 4, for the negative-parity levels. The energy scale in this case is given relative to the first 11/2- level. The calculated levels with lower spins are slightly shifted on the left with respect to higher spins in each spin bin. Only the stripping S-factors are shown, since the pick-up S-factors, especially the calculated ones, are negligible.
observed in single nucleon transfer reactions. While in calculations the parent 1 1 / 2 - state carries about 96% of the whole lh5]/2 strength, experimentally there is pronounced stripping-pick-up asymmetry. The visible (d,p) deficit of the 1 h51/2 strength relative to the corresponding (d,t) or (3He,a) strengths would mean that the missing part in the
(d,p) reaction should be distributed among higher-lying levels. On the other hand, this
could mean that the hi 1/2 subshell is nearly full which is in itself surprising enough. Unfortunately, as mentioned in Section 4.1, no additional 1 1 / 2 - states could be firmly identified in the present study. Thus the question is still open.
A further step to confirm the theoretical approach could be obtained from a comparison of the electromagnetic properties of the levels and their electromagnetic transition rates. These quantities for some of the lowest levels are compared in Table 7. A direct comparison of absolute calculated and experimental transitions rates is possible only for the 9/2~- and 7/2~- states. They have the following characteristic feature: the enhanced E2 transitions between low-spin members are nicely reproduced. The B(E2) rates of about 6 -15 W. u. have values of the same order as for the deexcitation of positive-parity members belonging to the same particle+core multiplets. Also, the equivalence of the calculated B ( E 2 ) with respect to the high-spin family of states strongly supports a similar origin of both these aligned and antialigned states.
J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
Table 7 M 1 and E2 transitions between low-lying states of negative parity in 125Te
373
Ei Transition E r B(M1)(/x 2 ) B(E2) (e2b 2 ) Branching
(keV) Ji Jf (keV) Theor. Exp. [601 Theor. Exp. [601 Theor. Exp.
321.11 9/21 l l /2j 176.30 0.142x10 -°2 0.81x10 -°2 0.497xl0 - j 0.123 100 100 525.31 7/21 11/21 380.44 0.505x10 m )0.37x10 -I 50.6 100
9/21 204.14 0.654x10 -m />0.159x10 -°2 0.168x10 -°2 />0.92xl0 m 100 21.4 786.72 7/22 11/21 641.85 0.220x 10 .o5 ~0 59.4
9/21 465.55 0.296x 10 .o2 0.652x 10 -In 100 100 7/21 261.42 0.306x 10 .03 0.906x 10 .o2 1.0 7.9
659.7 15/21 11/21 659.7 0.494xl0 -°1 100 100 1071.65 5/21 9/21 750.68 0.212x10 -°1 88.4 19.6
7/21 546.56 0.139xl0 -°2 0.541x10 -°1 52 100 7/22 285.37 0.172 0.177x 10 -113 100 15.2
1319.53 3/21 7/21 794.22 0.753X 10 -m 100 100 7/22 532.8 0.135x 10 -o2 0.2 15 5/21 247.67 0.233 0.287X10 -°2 21.1 13 I
1355.6 19/21 15/21 695.9 0.756x10 -°1 100 100
6. Conclusions
A comprehensive study of the nuclear structure of 125Te via (n ,y ) , (d,p) and (3He,a)
reactions is presented. About 200 levels up to 3.3 MeV excitation energy and over 360
deexcit ing y-transit ions have been identified, most of them for the first time. The very
complete experimental set of data below 2.3 MeV was interpreted in terms of the
IBFM. Although some uncertainties remain, it seems clear from the present study that
this model can provide a detailed quantitative description of the level energies, y-ray
branching and spectroscopic factors for stripping and pick-up reactions. In the present
study a unitary treatment of both positive- and negative-parity states could be achieved
with the same set of model parameters. The calculated stripping and pick-up strength
distributions have a tendency to be sharper, especially for the deep-lying 1g9/2 orbit, in
contrast to the broader experimental distributions. This could be related both to the need
tor more realistic one-particle transfer operators and the influence of states outside the
IBFM space. Whi le the posit ive-parity states are described as expected by mixing of the
four valence neutron orbits 3sl/2, 2d3/2, 2d5/2 and 2g7/2 with boson core states, the low-
lying negative-parity states are dominated by the unique-parity orbit lhl l /2. Evidence is
presented which sugge,'ts that the lowest 3 / 2 - , 5 / 2 - , etc. members contain the main
wave function contribution from the lh l l /2 orbit proving their antialigned origin. In
general, the level energies, decay modes and level density up to 2 MeV are described
in the IBFM with good accuracy compared with other models.
374 J. Honzdtko et al./Nuclear Physics A 645 (1999) 331-375
Acknowledgements
We are grateful to P. Maier-Komor and to K. Nacke for the target preparation and to T. Faestermann for the Q3D maintenance. The technical staff of the reactor at l~e2 and of the accelerator laboratory in Munich deserve appreciation for providing us with excellent beams. One of us (V.B.) is grateful to the NPI, l~e~ and the TU, Munich for the hospitality extended. This work was supported by the Grant Agency of the Czech Republic (No. 202/97/K038), partly by the Volkswagen Foundation and by the Deutsche Forschungsgemeinschaft, Bonn (Eg 25/4, Gr 894/2).
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