The double spin asymmetry of nitrogen in elastic and quasielastic kinematics from a solid ammonia dynamically polarized target

Abstract

Solid ammonia (NH 3 ) is commonly used as a dynamically polarized proton target for electron and muon scattering cross-section asymmetry measurements. As spin 1 + particles, the 14 N nuclei in the target are also polarized and contribute a non-trivial asymmetry background that should be addressed. We describe here a method to extract the nitrogen contribution to the asymmetry, and report the cross-section asymmetries of electron-nitrogen scattering at beam energies of E = 1.7 GeV and E = 2.2 GeV, and momentum transfer of Q 2 = 0.023−0.080 GeV 2 .