Induced Polarization in 4He(e,e'p)3H
Polarization transfer in the 4He(e¿ ,e'p¿ )3H reaction up to Q2=2.6 (GeV/c)2 has been measured in an attempt to study possible medium modifications of the proton form factors. Indeed, the measured ratio of polarization-transfer coefficients are described by the inclusion of a medium modification of the proton form factors. This interpretation is challenged by a recent calculation including, particularly, a spin-dependent charge exchange in the final-state interaction. The induced polarization in this reaction is a measure of final-state interactions. Precise data on these are key to shed more light on this controversy. In our recent follow-up experiment E03-104 at Jefferson Lab data were taken at a Q2 of 0.8 (GeV/c)2 and 1.3 (GeV/c)2 on 1H and 4He targets. The extraction of the small induced polarization of the recoiling proton for the 4He(e,e'p¿ ) reaction is complicated by the possible presence of instrumental asymmetries in the focal-plane polarimeter. The induced polarization in the elastic 1H(e,e′p⃗ ) reaction is (in one-photon approximation) zero and provides crucial information about these false asymmetries. Our extraction procedure and preliminary results will be presented.
- Research Organization:
- Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1999600
- Report Number(s):
- JLAB-PHY-07-1013; DOE/OR/23177-7141
- Country of Publication:
- United States
- Language:
- English
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