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Title: Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors

We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q^2 dependence of the axial-vector form factor g_a(Q^2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g_a(Q^2). If g_a(Q^2) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q^2 mapping of g_a between 0.01
  1. JLAB
Publication Date:
OSTI Identifier:
Report Number(s):
JLAB-PHY-13-1753; DOE/OR/23177-2614; arXiv:1307.2927
DOE Contract Number:
Resource Type:
Resource Relation:
Journal Name: AIP Conf. Proc.; Journal Volume: 1563; Conference: Workshop to explore physics opportunities with intense, polarized electron beams at 50-300 MeV, 14-16 March 2013, Cambridge, Massachusetts
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Axial form factor, electromagnetic form factors, beta decay, Inverse reaction, parity violation