The recoil proton polarization was measured in the H2(e→, e′p→)n reaction in Hall A of the Thomas Jefferson National Accelerator Facility. The electron kinematics were centered on the quasielastic peak (xBj1) and included three values of the squared four-momentum transfer, Q2=0.43,1.00 and 1.61 (GeV/c)2. For Q2=0.43 and 1.61 (GeV/c)2, the missing momentum, pm, was centered at zero, whereas for Q2=1.00(GeV/c)2 two values of pm were chosen: 0 and 174MeV/c. At low pm, the Q2 dependence of the longitudinal polarization, Pz′, is not well described by a state-of-the-art calculation. Further, at higher pm, a 3.5σ discrepancy was observed in the transverse polarization, Px′. Understanding the origin of these discrepancies is important to confidently extract the neutron electric form factor from the analogous H2(e→,e′n→)p experiment.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics