TY - JOUR
T1 - Measurement of polarization transfer in the quasi-elastic Ca40(e→,e′p→) process
AU - A1 Collaboration
AU - Kolar, T.
AU - Achenbach, P.
AU - Christmann, M.
AU - Distler, M. O.
AU - Doria, L.
AU - Eckert, P.
AU - Esser, A.
AU - Giusti, C.
AU - Geimer, J.
AU - Gülker, P.
AU - Hoek, M.
AU - Klag, P.
AU - Lichtenstadt, J.
AU - Littich, M.
AU - Manoussos, T.
AU - Markus, D.
AU - Merkel, H.
AU - Mihovilovič, M.
AU - Müller, J.
AU - Müller, U.
AU - Pätschke, J.
AU - Paul, S. J.
AU - Piasetzky, E.
AU - Plura, S.
AU - Pochodzalla, J.
AU - Požun, M.
AU - Ron, G.
AU - Schlimme, B. S.
AU - Sfienti, C.
AU - Stengel, S.
AU - Stephan, E.
AU - Strauch, S.
AU - Szyszka, C.
AU - Širca, S.
AU - Thiel, M.
AU - Wilczek, A.
N1 - Publisher Copyright:
© 2023 The Author(s)
PY - 2023/12/10
Y1 - 2023/12/10
N2 - Polarization transfer to a bound proton in polarized electron knock-out reactions, A(e→,e′p→), is a powerful tool to look for an in-medium modification of the bound proton. It requires comparison to calculations that consider the many-body effects accompanying the quasi-free process. We report here measured components Px′, Pz′, and their ratio Px′/Pz′, of polarization transfer to protons bound in Ca40, which is described well by the shell model and for which reliable calculations are available. While the calculations capture the essence of the data, our statistical precision allows us to observe deviations that cannot be explained by simple scaling, including by varying the proton electromagnetic form factor ratio GE/GM. We further explore the deviations of the ratio of the polarization transfer components from that of a free proton, (Px′/Pz′)A/(Px′/Pz′)H, and its dependence on the bound-proton virtuality.
AB - Polarization transfer to a bound proton in polarized electron knock-out reactions, A(e→,e′p→), is a powerful tool to look for an in-medium modification of the bound proton. It requires comparison to calculations that consider the many-body effects accompanying the quasi-free process. We report here measured components Px′, Pz′, and their ratio Px′/Pz′, of polarization transfer to protons bound in Ca40, which is described well by the shell model and for which reliable calculations are available. While the calculations capture the essence of the data, our statistical precision allows us to observe deviations that cannot be explained by simple scaling, including by varying the proton electromagnetic form factor ratio GE/GM. We further explore the deviations of the ratio of the polarization transfer components from that of a free proton, (Px′/Pz′)A/(Px′/Pz′)H, and its dependence on the bound-proton virtuality.
UR - http://www.scopus.com/inward/record.url?scp=85176249775&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2023.138309
DO - 10.1016/j.physletb.2023.138309
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AN - SCOPUS:85176249775
SN - 0370-2693
VL - 847
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
M1 - 138309
ER -