Proceedings of the 21st International Symposium on Spin Physics (spin2014)
Jefferson Lab has been at the forefront of a program to study the polarized structure of nucleons using electron scattering. Measurements of the spin dependent structure functions, g(1) and g(2), have proven to be powerful tools in testing and understanding QCD. The neutron structure function g(2)(n) has been measured extensively in Hall A at Jefferson Lab over a wide range of Q(2), but data for g(2)(p) remains scarce. This docment will discuss the g(2)(p) experiment, which ran in Hall A at Jefferson Lab in the spring of 2012, and will provide the first measurement of g(2)(p) in the resonance region; covering 0.02 < Q(2) < 0.2 GeV2. The 0th moment of g(2) provides a test of the Burkhardt-Cottingham sum rule, which states that the integral of g(2) over the Bjorken scaling variable x goes to zero. This sum rule, valid for all values of Q(2), has been satisfied for the neutron, but a violation is suggested for the proton at high Q(2). The 2nd moment allows for a benchmark test of chi PT at low Q(2). Specifically, the behavior of the longitudinally-transverse spin polarizability (delta(LT)), as chi PT calculations of this quantity deviate significantly from the measured neutron data. This document will discuss the current status of the analysis along with preliminary results.
A Measurement of g2p at Low Q2 M. Cummings (1Department of Physics, The College of William and Mary, P.O. Box 8795, Williamsburg, Virginia 23187-8795, USA) International Journal of Modern Physics: Conference Series 2016 40: