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Title: Proton form factor ratio μ p G E p / G M p from double spin asymmetry

Journal Article · · Physical Review C

We report the ratio of the electric and magnetic form factor of the proton, $$\mu_p G_E^p/G_M^p$$, has been measured for elastic electron-proton scattering with polarized beam and target up to four-momentum transfer squared, $Q^2=5.66$ (GeV/c)$^2$ using the double spin asymmetry for target spin orientation aligned nearly perpendicular to the beam momentum direction. This measurement of $$\mu_p G_E^p/G_M^p$$ agrees with the $Q^2$ dependence of previous recoil polarization data and reconfirms the discrepancy at high $Q^2$ between the Rosenbluth and the polarization-transfer method with a different measurement technique and systematic uncertainties uncorrelated to those of the recoil-polarization measurements. The form factor ratio at $Q^2$=2.06 (GeV/c)$^2$ has been measured as $$\mu_p G_E^p/G_M^p = 0.720 \pm 0.176_{stat} \pm 0.039_{sys}$$, which is in agreement with an earlier measurement with the polarized target technique at similar kinematics. The form factor ratio at $Q^2$=5.66 (GeV/c)$^2$ has been determined as $$\mu_p G_E^p/G_M^p=0.244\pm0.353_{stat}\pm0.013_{sys}$$, which represents the highest $Q^2$ reach with the double spin asymmetry with polarized target to date.

Research Organization:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mississippi State Univ., Mississippi State, MS (United States); Mississippi State Univ., Starkville, MS (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP); National Science Foundation (NSF); Natural Sciences and Engineering Research Council of Canada (NSERC)
Contributing Organization:
SANE Collaboration
Grant/Contract Number:
SC0003884; SC0013941; FG02-96ER40950; AC05-06OR23177; PHY-0855473; PHY-1207672; HRD-1649909; FG02-07ER41528
OSTI ID:
1605544
Alternate ID(s):
OSTI ID: 1604858; OSTI ID: 1778967; OSTI ID: 1781684; OSTI ID: 1873162
Report Number(s):
JLAB-PHY-20-3164; DOE/OR/23177-4944; arXiv:1806.11156; PRVCAN; TRN: US2104446
Journal Information:
Physical Review C, Vol. 101, Issue 3; ISSN 2469-9985
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 7 works
Citation information provided by
Web of Science

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