Spin Correlation Parameter C yy of p + 3 He Elastic Backward Scattering at Intermediate Energy
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Transcript of Spin Correlation Parameter C yy of p + 3 He Elastic Backward Scattering at Intermediate Energy
Spin Correlation Parameter Cyy of p + 3He Elastic Backward
Scattering at Intermediate Energy
Youhei Shimizu
RCNP, Osaka University
CollaboratorsCollaboratorsRCNP, Osaka University : Y. Shimizu, K. Hatanaka, Y. Sakemi, A. Tamii, H.P. Yoshida, M. Uchida, Y. Shimbara, K. Fujita, Y. Tameshige, H. matsubara
CNS, University of Tokyo : T. Uesaka, T. Wakui, T. Kawabata, Y. Sasamoto
Saitama University : K. Itoh
Kyushu University : K. Sagara, T. Wakasa, T. Kudoh, M. Tomiyama, H. Ohira
Osaka University : T. Adachi
Tohoku University : H. Okamura
RIKEN : H. Ueno, K. Suda
Contents1. Introduction 1.1. Few Body System
1.2. Elastic Backward Scattering
2. Experimental Setup 2.1. RCNP Ring Cyclotron Facility
2.2. Polarized 3He Target
3. Results 3.1. Calibration of 3He Polarization
3.2. p+3He Elastic Backward Scattering
3.3. Comparison with Theoretical Prediction
4. Summary
Introduction
2NF only with 3NF Exp.
7.953 8.483 8.482
Few body system
Triton binding energy (MeV)
Some problems in the spin structure of 3NF
p+d Elastic Scattering
K. Hatanaka et al., PRC 44, 44002 (2002)
d+p Break-up Reactiond+p Capture Reaction......
Elastic Backward Scattering (EBS)
• Elastic Backward Scattering (EBS)
• Spin Correlation Parameter Cyy
Structure of the lightest nuclei (d, 3He, ) at short distances between the constituent nucleons
high momentum componentsof the target wave function
target-related spin observable is sensitive tothe spin-dependent parts of the target wave function
p + 3He EBS at RCNP
Experimental Condition
• Beam : Polarized proton 200, 300, 400 MeV
10 40 nA, polarization 70 • Target : Polarized 3He gas target
polarization 10 • Angle : 0 degrees
• Solid angle : 2.8 msr
• Reaction : 3He(p,+)4He 3He(p,3He)p
• Observables : 3He polarization
d/d, Cyy
Experimental SetupOverview of theOverview of theRCNP Ring Cyclotron FacilityRCNP Ring Cyclotron FacilityOverview of theOverview of theRCNP Ring Cyclotron FacilityRCNP Ring Cyclotron Facility
Grand RaidenGrand RaidenGrand RaidenGrand Raiden
D1 Faraday CupD1 Faraday Cup
The Schematic view of the Polarized 3He Target
Density : 8.96e+19 cm-3
Max Polarization : 19 %
Measurement of 3He Polarization
• AFP (Adiabatic Fast Passage) - NMR
• 3He(p,+)4He
Monitor throughout the experimentNMR signal is proportional to the amount of polarization.Need to be calibrated by another method.
Calibration by using polarized proton beam
002
1
2
1 1yyC
Very Preliminary
Very Preliminary
3He(p,+)4He
NMR2
He 1016.062.6 VP NMR2
He 1016.062.6 VP
Relation to AFP-NMR Amp.
R
R
pP
y
1
11beamHe
II
IIR beam
targetI
K.M. Furutani et al., PRC 50, 1561(1994)
Very Preliminary
Very Preliminary
p+3He Elastic Backward Scattering
Cross Section is consistent with other experimental data. New data for spin correlation parameter Cyy
Cross Section is consistent with other experimental data. New data for spin correlation parameter Cyy
Comparison with Theoretical Prediction
• For Cyy, there are large discrepancy
PI
DIR
ODE+PI+DIR
2N+PI
Calculated by A.P. Kobushkin
Reaction Mechanism• One-Deuteron-Exchange
d d or d*
Ep < ~200 MeV
• rescattering of the intermediate PIon off the intermediate deuteron
200 MeV < Ep < 1000 MeV
• DIRect proton interaction
Ep > 1000 MeV
p (m, p)
3He (M, P)
3He (M’, P’)
p (m’, p’)
d or d*
p (m, p) 3He (M’, P’)
3He (M, P) p (m’, p’)
p (m, l)~
p (m’, l’)~
d (’, p’d)
d (, pd) (q)
(q’)
d or d*3He (M, P) 3He (M’, P’)
p (m, p) p (m’, p’)
p (m1, l) p (m’1, l’)
Contribution of the Singlet Deuteron
• ODE (Ep < ~ 0.2 GeV)
• PI (0.2 GeV < Ep < 1 GeV)
• DIR (Ep > 1 GeV)
For pure deuteron exchange,Cyy =
independent on the beam energy
d d or d
(pn)sCalculated by A.P. Kobushkin
Summary
• For p+3He EBS at 200, 300, 400 MeV, d/d, Cyy were measured at RCNP.
• 3He polarization was calibrated by 3He(p,+)4He reaction.
Max Polarization : 19 %• Experimental results were compared with
existing data and theoretical predictions.
d/dconsistent with existing data
Cyy : large discrepancy with
theoretical predictions