Search for Proton Medium Modifications in the 4He(e,e'p)3H Reaction.

Strauch, S.

Technical Information Center Oak Ridge Tennessee

关键词: Protons;    Quark model;    Coupling constants;    Form factors;    Quasi-elastic scattering;   

RP-ID  :  DE2007917016

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Polarization transfer in quasi-elastic nucleon knockout is sensitive to the properties of the nucleon in the nuclear medium, including possible modification of the nucleon form factor and/or spinor. In our recently completed experiment E03-104 at Jefferson Lab we measured the proton recoil polarization in the 4He(e,e'p)3H reaction at a Q(caret)2 of 0.8 (GeV/c)(caret)2 and 1.3 (GeV/c)(caret)2 with unprecedented precision. These data complement earlier data between 0.4 and 2.6 (GeV/c)(caret)2 from both Mainz and Jefferson Lab. The measured ratio of polarization-transfer coefficients differs from a fully relativistic calculation, favoring either the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model or strong charge-exchange final-state interactions. The measured induced polarizations agree well with the fully relativistic calculation and indicate that these strong final-state interactions may not be applicable.