Quasi-elastic polarization-transfer measurements on the deuteron in anti-parallel kinematics
S. Paul (School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel)
; D. Izraeli (School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel)
; T. Brecelj (Jožef Stefan Institute, Ljubljana, Slovenia); I. Yaron (School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel); P. Achenbach (Institut für Kernphysik, Johannes Gutenberg-Universität, Mainz, Germany)
; et al - Show all 44 authors
We present measurements of the polarization-transfer components in the reaction, covering a previously unexplored kinematic region with large positive (anti-parallel) missing momentum, , up to , and . These measurements, performed at the Mainz Microtron (MAMI), were motivated by theoretical calculations which predict small final-state interaction (FSI) effects in these kinematics, making them favorable for searching for medium modifications of bound nucleons in nuclei. We find in this kinematic region that the measured polarization-transfer components and and their ratio agree with the theoretical calculations, which use free-proton form factors. Using this, we establish upper limits on possible medium effects that modify the bound proton's form factor ratio at the level of a few percent. We also compare the measured polarization-transfer components and their ratio for $^{2}$H to those of a free (moving) proton. We find that the universal behavior of $^{2}$H, $^{4}$He and $^{12}$C in the double ratio is maintained in the positive missing-momentum region.