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pd 捕獲反応のテンソル偏極量の異常. K. Sagara 1 , Y. Tameshige 2 , K. Hatanaka 2 , S. Kuroita 1 , H. Matsubara 2 , K. Fujita1, Y. Shimizu 2 , T. Kawabata 3 , Y. Maeda 5 , Y. Sakemi, H. Okamura 2 , K. Sekiguchi 4 , Tamii 2 , and T. Wakasa 1 1 Dept. of Physics, Kyushu University 2 RCNP, Osaka University - PowerPoint PPT Presentation
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pd 捕獲反応のテンソル偏極量の異常
K. Sagara1, Y. Tameshige2, K. Hatanaka2, S. Kuroita1, H. Matsubara2, K. Fujita1, Y. Shimizu2, T. Kawabata3, Y. Maeda5, Y. Sakemi, H. Okamura2, K. Sekiguchi4, A. Tamii2, and T. Wakasa1
1Dept. of Physics, Kyushu University2RCNP, Osaka University3CNS, University of Tokyo4RIKEN, 5CYLIC, Tohoku University6Dept. of Engineering, Miyazaki University
Ay puzzle1986
Ay puzzle
pd CS discrepancy1994-1996-1997
(Sagara discrepancy)
3N BE problem1980’s
3NF(FM)was found
1998
pd breakup discrepancy
pd captureAjj anomaly
3NF?3NF?relativity?
Space Star anomaly1980’s
higher energy discrepancies
pd sactt. discrepancy
lower energy discrepancies
lower energy discrepancies
Off-plane star anomaly
???
???
Discrepancies in 3N systems and their origins
FM-3NF1957
By Koike’s talk at Few-Body Conf. at KVI (1997), CS minimum discrepancy was widely recognized.
+
+
+ +
+
3NF found
High momentum transfer
Wide phase space
Experiments in pd system
pd capture experiment
+ +
○ Short-range forces may play important roles. (→new 3NF)
× Reaction cross section is very small (< 1 barn).
Experimental techniques•thick target & low BG → liquid hydrogen target •high-efficiency detection → one-shot measurement of whole angular distribution
Side View(enlargement)
12
Front View
Liquid Hydrogen Target 精密実験に不可欠
m
Vertical planefor Axx
Horizontal planefor Ayy & Ay
(3He) < 4.7
Whole angular distribution was measured in one shot.
Axx anomaly in pd capture at Ed = 200 MeVfrom RCNP exp. (Yagita et al. 2002)
2 NF2 NF +3 NF
Calc. by Witala et al.
0 50 100 150
0.2
0.0
0.2
0.4
0.6
Axx
C.M angle (deg.)0 50 100 150
0.2
0.0
0.2
0.4
Ayy
C.M angle (deg.)
0 50 100 150
0.2
0.1
0.0
0.1
0.2
Ay
C.M angle (deg.)0 50 100 150
0.5
0.4
0.3
0.2
0.1
Cro
ss
sect
ion
(m
b/s
r)
0.0
C.M angle (deg.)
Axx anomaly? Axx~Ayy?
Ajj of pd-capture were measured also at KVI, and KVI data agreed with calculations.
Axx Ayy
Azz
● ○ RCNP(200MeV)■ □ KVI ( 180MeV)
RCNP data at 137MeV also disagreed with KVI data at 133MeV.
KVI での測定 , Ayy & Azz (=-Axx-Ayy )共通点• 液体水素標的• pyy ビーム
KVI
• A yy , A zz
• 散乱平面は PB で決定• 3He- のののののののの測定 綺麗に測定(統計が少ない) Azz→ 実際は -(Axx+Ayy) を測定
Big-Bite spectrometer (BBS) & Plastic Ball detector (PB)
検出角度Azz :45±10 度Ayy : 0±15 度
Azz = -Axx-Ayy
ビーム軸 から見た PB 検出器
d+p → 3He + Ed = 140 MeVat RCNP
preliminary
Ayy Axx
BG 多く、データ解析進まず
We made a new experiment (present exp.) at RCNP.
Beam : 197 MeV (same as before)Target : Liquid Hydrogen (same as before)Detection: 3He (same as before)
Observables: Axx (same as before) Ayy (same as before) Azz (= -Axx-Ayy) (similar to KVI)
d + p→3He+EdeV
(3He) < 4.7deg
Slit in front of LAS
Azz=(Axx-Ayy)Axx Ayy
Beam polarization
Liuqidtarget
Emptytarget
Background subtraction
BG
True
y
y
polarized beam
unpol. beam
Y
In previous exp. BG level was low.
LAS 0° Data Analysis
projection
Data at 140 MeV, BG 多い
A = [ (Ytrue)pol / (Ytrue)unpol – 1 ] / pbeam
= [ (Ytot-YBG)pol / (Ytot-YBG)unpol – 1] / pbeam
Y = (Ncount /Qbeam) /efficiency
Efficiency should be high to obtain reliable data.
Detection efficiency
Single cluster
Multiple cluster
Overlapped cluster & single cluster
Overlapped–overlapped clusterOther rays
~83%
~2%
~14%
~1%
Efficiency =.834 =0.48Standard data analysis
Efficiency =.974 =0.88
Efficiency =.994 =0.96Multi-II data analysis
X1
X1
X1
X1
X2
X2
Detection efficiency was much improved by a multi-II method.
Total 100%
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0 30 60 90 120 150 180
Axx 196MeV
AxxYag
AxxMII
theta
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0 30 60 90 120 150 180
Ayy 196MeV
AyyYag
AyyMII
theta
Single cluster data analysis vs. Multi-cluster II data analysis
2002 exp.
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0 30 60 90 120 150 180
Axx 196MeV
AxxAxx126Axx2NFAxx3NF
theta
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0 30 60 90 120 150 180
Ayy 196MeV
AyyAyy126Ayy2NFAyy3NF
theta
d+p→3He+
New data and previous data (Multi-II)2002present
-0.2
0
0.2
0.4
0.6
0.8
1
0 30 60 90 120 150 180
Azz 196MeV
AzzAxxyyAzz126Azz2NFAzz3NF
theta
d+p→3He+
New data and previous data (Multi-II)present 2002
-0.2
0
0.2
0.4
0.6
0.8
1
0 30 60 90 120 150 180
Azz data
AzzAxxyyAzz126Azz2NFAzz3NFAzzKVI
theta
KVI data at 180 MeV
RCNP data at 196 MeV
Calc. at196 MeV
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0 30 60 90 120 150 180
Ayy 137MeV
Ayy137Ayy2NFAyy3NF
theta
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0 30 60 90 120 150 180
Axx 137MeV
Axx137Axx2NFAxx3NF
theta
pd radiative capture at Ed = 137 MeV(multi-II analysis)
Summary
Axx, Ayy, and Azz (= -Axx-Ayy) of pd radiative capture at Ed = 196 MeV were measured again at RCNP.
Data were analyzed with 96% detection efficiency by multi-cluster-II method.
Also previous RCNP data at 196 MeV were re-analyzed by multi-cluster-II method.
New and previous data agree well, and
Axx (Azz) anomaly in pd capture was confirmed.
Also at 137 MeV, Axx anomaly in pd capture was confirmed.
Axx ≈Ayy relation was also confirmed.
The Axx (Azz) anomaly can not be explained by 3NF, and new forces or mechanisms may be necessary.
Ay puzzle1986
Ay puzzle
pd CS discrepancy1994-1996-1997
(Sagara discrepancy)
3N BE problem1980’s
3NF(FM)was found
1998
pd breakup discrepancy
pd captureAjj anomaly
3NF?3NF?relativity?
Space Star anomaly1980’s
higher energy discrepancies
pd sactt. discrepancy
lower energy discrepancies
lower energy discrepancies
Off-plane star anomalyQFS anomaly?
???
???
Discrepancies in 3N systems and their origins
FM-3NF1957