Improving Accuracy of Parity Violation Measurements for NOPTREX Experiment at LANLDANIELA OLIVERA, Berea College for NOPTREX collaboration.

The main goal of the Neutron Optics Time Reversal Experiment is to look for new sources of time reversal (T), which could explain the matter/antimatter asymmetry in the universe.  As part of our search, we need higher (within 1\%) accuracy measurements of the parity violating spin-dependent forward neutron scattering amplitude in La-139 \cite{Yuan} and other nuclei, which share the same matrix element as time-reversal odd amplitudes.  Since lanthanum has a large (~10\%) PV transmission asymmetry,  we can use it as both the polarizer and analyzer, which eliminates the measurement of the neutron polarization and associated systematic uncertainties that accompany the use of a traditional 3He polarizer.  This presentation will discuss the analysis of the beam intensity profiles (necessary to calculate the neutron spin-flip efficiency) and the fitting of the nuclear resonance data collected in Summer 2018 at Los Alamos National Lab, including the effects of Doppler broadening on the resonances.

\bibitem{Yuan} Yuan, Bowman, et al., Phys. Rev. C. {\bf 44}, 2187 (1991).