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Shell model study of p-shell X hypernuclei ( 12 X Be). 杉本聡 京都大学 元場俊雄 大阪電通大 山本安夫 都留文科大. Introduction. Up to now, the experimental information are limited for X hyper nuclei as compared to L hyper nuclei. - PowerPoint PPT Presentation
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Shell model studyof p-shell hypernuclei (12
Be)
杉本聡京都大学元場俊雄
大阪電通大山本安夫
都留文科大
Introduction Up to now, the experimental information are limited fo
r hyper nuclei as compared to hyper nuclei. Theoretically, a pioneer work was done by Dover and
Gal (Ann. Phys. 146 (1983)) using the existent data at that time.
V~-21~24MeV The experiments of (K-,K+) reaction were performed at
KEK (Fukuda et al. PRC 58 (1998)) and AGS (Khaustov et al. PRC 61 (2000))
U~-14MeV (Assuming a simple WS potential) At JPARC, the experiment of (K-,K+) reaction is planne
d to explore hypernuclei.
Purpose of our study To study the structure of hypernuclei using t
he shell model with effective interactions deduced from realistic NY interaction model.
To perform a reaction calculation with the wave function from the shell model to explore what can be obtained from the experimental data. DWIA for (K-,K+)
This method has been quite successfulin the study of hypernuclei!
ExperimentChrien et al., NPA 478 (1988)
From Hashimoto et al., PPNP 57
Shell model+DWIAItonaga et al.,PRC 49 (1994)
Woods-Saxon (K-P)+DWIAMotoba et al., PRC 38 (1988)
ExperimentHotchi et al., PRC 64 (2001)
12C(,K+)12C
Shell model calculation 12
Be (11B+-) (12C(K+,K-)12Be)
Active space for nucleons: p-shell is fixed to the 0s1/2 orbit. Effective interaction for nucleons: Cohen-Kurath Effective interaction for N-: YNG interaction by Yama
moto (G matrix, kF dependence) YN interaction model (VN- がががが )
ESC04d (Rijken and Yamamto PRC 73 044008 (2006)) NHC-D (Nagels et al. PRD 15 2547 (1977))
Non-central part is not included.
がCK YNG
NY N Y NYH H t v がが が がが
Single particle energy 12
Be
kF in YNG is determined by the condition BE(
)~4.5 MeV. Uis comparable to the experimental data.
U ~ 14MeV (Fukuda et al., Khaustov et al)
J T kF tY UY tY+UY E BE (Y)
ESC04d () 1-1 1 1.08 11.8 -16.1 -4.4 -57.4 4.5
NHC-D() 1-1 1 1.05 11.8 -15.3 -3.5 -57.4 4.5
NS97f() 1-1 1/2 1.24 10.5 -22.5 -11.9 -65.1 12.2
p-shell matrix element of YNG
forN-is larger than that for N- ESC04d gives quite large for ESC04d and NHC-D have opposite signs.
T Vb
Vb
N-ESC04d0 4.98 -15.81 -3.18
1 0.30 -2.96 -9.88
N-NHC-D0 2.14 4.75 2.23
1 1.55 0.79 0.51
N-NSC 1/2 1.05 0.04 0.04
~NYV V が
12Be(11B+)
The spectra for ESC04d and NHC-D show different behavior. The orders of the lowest two levels are different because of the
sign changes of spin-spin part between ESC04d and NHC-D. ESC04d: intermediate (strong) coupling NHC-D: weak coupling (at least in the T=0 channel)
-65
-60
-55
-50
-45
0-
3-2-
1-
2-
0-
1-
2-1-
3/2-1/2-
5/2-
12
B
T=1
T=1/2
11B
E (
MeV
)
12
Be
T=0 ESC04d
3/2-
0-
1-
2-
3-
-65
-60
-55
-50
-45
3-
2-
1-0-
1-
2-
2-
0-1-
2-3/2-
3/2-
1/2-
12
B
E (
MeV
)
12
Be
11B
T=1/2
T=1T=0
NHC-D
5/2-
1-
11B+
DWIA 計算 12C(K-,K+)12
Be 殻模型計算で得られた波動関数を用いて
DWIA 計算を行った。
(K-,K+) 反応 運動量移行が大きい( ~500MeV/c@pK-
=1.6GeV/c) ので J-stretched の状態が強く励起される。
アイソスピン移行は 1
SMeff
( ) ( )( ; )
L L K p K
d dZ i f
d d
1
1 , 1[0 0 ]
J Tp s
T=1, 1- state in 12Be
12C(K-,K+)12Be 反応で強く励起されるの
は T=1,1- の状態。 ESC04d と NHC-D では波動関数の中身が
大きく違う。(相互作用の違いを反映)
11B+1.5MeV
4.5MeV
(13%,34%,49%)
(59%,39%,1%)
12Be
ESC04d
11B+1.5MeV
4.5MeV
(13%,86%,1%)
(86%,12%,2%)
12Be
NHC-D
(P(3/2-1s1/2),P(1/2-
1s1/2), P(3/2-2s1/2))
T=1/2
11C+
8.3MeV
10.7MeV(5%,95%,0%)
(94%,5%,0%)
4.4MeV(0%,0%,98%)
12C
NS97f
1.8MeV
GS
5.2MeV
11B or 11C
1st 3/2-
1st 1/2-
2nd 3/2-
Cohen-Kurath
Exicitation Function NHC-D
Smearing factor: 2MeV
11B+1.5MeV
4.5MeV
(13%,86%,1%)
(86%,12%,2%)
12Be
NHC-D
Excitation Function ESC04d11B+
1.5MeV
4.5MeV
(13%,34%,49%)
(59%,39%,1%)
12Be
ESC04d
Smearing factor: 2MeV
Excitation Function の比較
• 波動関数( NY相互作用)の違いが励起関数に反映される。
ESC04d NHC-D
Woods-Saxon potential(Khaustov et al, PRC 61)
0s1/2
0p1/2
Summary 12
Be に対して N- ががががががが ESC04d と NHC-D に基づいたものを用いて殻模型計算を行った。
ESC04d と NHC-D とでは波動関数の中身が大きく違う。 殻模型波動関数を用いて 12C(K-,K+)12
Be 反応に対する励起関数を求めた。
励起関数は波動関数の違いを反映し ESC04d と NHC-D とで大きく異なる。→ N- 相互作用の情報を得られる可能性?
今後の課題 p→ ががががが がががががががが p がが がががががががががががが
fss2 etc.