Polarization transfer in the 4He(e,e'p)3H reaction at Q2=0.8 and 1.3 (GeV/c)2.
PHYSICAL REVIEW LETTERS 2010;
105:072001. [PMID:
20868031 DOI:
10.1103/physrevlett.105.072001]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Indexed: 05/29/2023]
Abstract
Proton recoil polarization was measured in the quasielastic 4He(e,e'p)3H reaction at Q{2}=0.8 and 1.3 (GeV/c){2} with unprecedented precision. The polarization-transfer coefficients are found to differ from those of the 1H(e,e'p) reaction, contradicting a relativistic distorted-wave approximation and favoring either the inclusion of medium-modified proton form factors predicted by the quark-meson coupling model or a spin-dependent charge-exchange final-state interaction. For the first time, the polarization-transfer ratio is studied as a function of the virtuality of the proton.
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