A measurement of parity-violating asymmetries in the G0 experiment in forward mode

Abstract

The G0 experiment in Hall C at Jefferson Lab measures the parity-violating asymmetry in elastic electron scattering off hydrogen and quasielastic electron scattering off deuterium in the Q^2 range from 0.1 to 1 (GeV)^2 in both forward and backward running modes by using a longitudinally polarized electron beam on unpolarized liquid targets. By measuring three independent asymmetries, one in forward running mode off liquid hydrogen and two in backward running mode, one off liquid hydrogen and one off liquid deuterium, the experiment aims to perform for the first time a complete separation and mapping of the strange vector form factors of the nucleon (G_M^s, G_E^s) and the isovector axial form factor (G_A^e(T=1)) in three Q^2 bins over the Q^2 range from 0.1 to 1 (GeV/c)^2. To complete the physics program in both forward and backward modes it will take about five years. To accomplish the forward running mode program some 100 C of data are needed. This thesis is based on 9 C of physics data taken during the first chekout of the G^0 apparatus during October 2002 - January 2003.