Proton recoil polarization was measured in the quasielastic He 4(e→,e′p→)H3 reaction at Q2=0.8 and 1.3(GeV/c)2 with unprecedented precision. The polarization-transfer coefficients are found to differ from those of the H1(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.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)