Parity nonconservation in proton scattering at higher energies

Abstract

Parity-nonconservation experiments In the scattering of longitudinally polarized protons at incident proton momenta of 1.5 and 6 GeV/c are examined. These experiments indicate a change w~th energy of the total cross section correlated with proton helicity that was unexpected. This energy dependence is due to the strong part of the Interaction and may indicate the role of a diquark component In the nucleon. New experiments at higher energies are needed to confirm such a model. Future experiments can benefit from an analysis of sources of systematic error that have been encountered In the experiments discussed here.Des exptriences sur la non-conservation de la pant6 dans la diffusion de protons polarises longltudinalement pour des protons incidents de 1,5 et 6 GeV/c sont examinees. Ces exptriences indiquent un changement de la section efficace totale en fonction de I'energie par rapport a I'hClicitC du proton qui n'ttait pas attendu. Cette dtpendance en Cnergle est due i la partie forte de I'lnteraction et peut ~ndiquer le r6le de la composante diquark dans le nuclton. De nouvelles experiences a des energies plus tlevees sont dtsirables pour confirmer un tel modele. Des experiences futures peuvent bCnCficier de l'analyse des sources d'erreurs systtmatiques qui ont Ct C rencontrees dans l'experience discutte ici Can J Phys 66,495 (1988) [Traduit par la @ue]

Parity Violation and the Nucleon-Nucleon System

“…A very interesting account of the history of the Los Alamos PNC experiments at 800 MeV energy on targets of H 2 O and liquid hydrogen, and of the 5.1 GeV experiment on H 2 O at the Argonne ZGS has been presented in ref. [35]. The total cross section was observed by detecting the change in the fraction of beam transmitted though the sample as the beam helicity is reversed (Fig.…”

“…For further comments on the analysis of the 6 Gev/c result, see refs. [35,42,43,44,45]. Certainly, a remeasurement of asymmetry in this energy region would be most welcome.…”

Parity violation in proton scattering: low energy region

“…' For proton energies of several hundred MeV or greater, Coulomb scattering is essentially negligible, so that the helicity dependence of the total cross section, AY, can be measured in an attenuation experiment (transmission experiment). The techniques and systematic errors in this type of experiment are sufficiently different from those in scattering experiments that high-energy measurements are reviewed separately in a paper by Mischke (17).…”