Polarization Transfer in the [superscript 4]He(e⃗,e′p⃗)[superscript 3]H Reaction at Q[superscript 2]=0.8 and 1.3  (GeV/c)[superscript 2]

Proton recoil polarization was measured in the quasielastic [superscript 4]He(e⃗,e′p⃗)[superscript 3]H reaction at Q [superscript 2]=0.8 and 1.3 (GeV/c)[superscript 2] with unprecedented precision. The polarization-transfer coefficients are found to differ from those of the [superscript 1]H(e⃗,e′p⃗) 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.United States. Dept. of EnergyNational Science Foundation (U.S.