Strong Interaction Effects in Parity Violation in p-p Elastic Scattering

Abstract

Parity violation (PV) in the hadronic interaction has been the focus of experimental and theoretical studies for many years. While the strong and electromagnetic interactions conserve parity, the weak interaction does not, and thus parity violation measurements serve as a probe of the weak part of the hadronic interaction. One example of an observable which is only sensitive to the weak interaction between hadrons is the longitudinal polarization asymmetry AZ in proton-proton scattering1). At low energies it has become standard practice to relate PV effects to an interaction between nucleons based on one and two vector-meson exchanges between a parity conserving (strong interaction) vertex and a parity violating (weak interaction) vertex. The strong interaction is presently well understood at these energies and is described by meson-exchange potentials, parametrized by phase-shift analysis. The PV interaction is parametrized by a set of meson-nucleon coupling constants. An extensive review paper by Desplanques et al.2) synthesized various approaches based on the quark model and SU(6) to calculating these coupling constants. The purpose of the present work is to concentrate on the strong interaction effects in PV in p-p scattering. Calculations have been performed using Thorndike’s3) and Woodruff’s4) approach: PV phase shift transitions are calculated involving known phases and a PV mixing angle is used as a parameter to set the magnitude of AZ. The PV phase shift mixings considered here are 1S0-3P0, 3P2-1D2, 1D2-3F2 etc.