Parity Nonconservation in Proton-Nucleus Scattering at 6 GeV/<i>c</i>

Abstract

A parity-nonconservation asymmetry has been measured in the total cross section for 6-GeV/c polarized protons on a water target. The asymmetry ${A}_{L}=\frac{({\ensuremath{\sigma}}_{+}\ensuremath{-}{\ensuremath{\sigma}}_{\ensuremath{-}})}{({\ensuremath{\sigma}}_{+}+{\ensuremath{\sigma}}_{\ensuremath{-}})}$, defined as the fractional difference of total cross sections for positive- and negative- helicity protons on an unpolarized target, is ${A}_{L}=(2.65\ifmmode\pm\else\textpm\fi{}0.60)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. The quoted error includes both statistical and systematic contributions.