E5

Spokesperson

W. K. Brooks and M. F. Vineyard

Year

2000

Abstract

The neutron elastic magnetic form factor $G_M^n$ has been extracted from quasielastic electron scattering data on deuterium with CLAS. The kinematic coverage of the measurement is continuous from $Q^2$=1~$\rm{GeV^2}$ to 4.8~$\rm{GeV^2}$. High precision was achieved by employing a ratio technique in which many uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Neutrons were detected using the CLAS electromagnetic calorimeters and the time-of-flight scintillators. Data were taken at two different electron beam energies, allowing up to four semi-independent measurements of $G_M^n$ to be made at each value of $ Q^2$. The dipole parameterization is found to provide a good description of the data over the measured $Q^2$ range.

Comment

Data analysis done by J.D. Lachniet, a student at CMU.

Publication

1. J.Lachniet, A.Afanasev, H.Arenh?vel, W.K.Brooks, G.P.Gilfoyle, S.Jeschonnek, B.Quinn, M.F.Vineyard, et al (the CLAS Collaboration) A Precise Measurement of the Neutron Magnetic Form Factor GMn in the Few-GeV2 Region // PRL 102, 192001 (2009)

Quantities

GMn_reduced

Measurements