학술논문
Quasi-elastic polarization-transfer measurements on the deuteron in anti-parallel kinematics
Document Type
article
Author
S. Paul; D. Izraeli; T. Brecelj; I. Yaron; P. Achenbach; H. Arenhövel; A. Ashkenazi; J. Beričič; R. Böhm; D. Bosnar; E. Cline; E.O. Cohen; L. Debenjak; M.O. Distler; A. Esser; I. Friščić; R. Gilman; M. Heilig; S. Kegel; P. Klag; Y. Kohl; T. Kolar; I. Korover; J. Lichtenstadt; I. Mardor; H. Merkel; D.G. Middleton; M. Mihovilovič; J. Müller; U. Müller; M. Olivenboim; E. Piasetzky; J. Pochodzalla; G. Ron; B.S. Schlimme; M. Schoth; F. Schulz; C. Sfienti; S. Širca; S. Štajner; S. Strauch; M. Thiel; A. Tyukin; A. Weber
Source
Physics Letters B, Vol 795, Iss , Pp 599-605 (2019)
Subject
Language
English
ISSN
0370-2693
Abstract
We present measurements of the polarization-transfer components in the H2(e→,e′p→) reaction, covering a previously unexplored kinematic region with large positive (anti-parallel) missing momentum, pmiss, up to 220MeV/c, and Q2=0.65 (GeV/c)2. 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 Px and Pz 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 GE/GM at the level of a few percent. We also compare the measured polarization-transfer components and their ratio for 2H to those of a free (moving) proton. We find that the universal behavior of 2H, 4He and 12C in the double ratio (Px/Pz)A(Px/Pz)H1 is maintained in the positive missing-momentum region.