Difference between Polarization and Analyzing Power for 800-MeVn−pElastic Scattering: Test of Time-Reversal Invariance

Abstract

A measurement has been made of the neutron polarization, $P$, from 800-MeV $p-n$ quasielastic scattering at 133° c.m. This together with previous measurements of the analyzing power, $A$, at the same angle in free $n-p$ scattering at 775 MeV constitutes a $P-A$ check of time-reversal invariance. No evidence is found for time-reversal invariance violation in $n-p$ scattering at medium energies, a clear-cut disagreement with the model predictions of Bryan and Gersten.