ISOBAR EXCITATION IN PARITY NONCONSERVING PROTON-PROTON SCATTERING

A parity violating (PV) meson exchange model is applied in the coupled channels formalism to study the effect of isobar excitation in PV pp scattering. The meson-mixing model used to calculate PV forbids the mi xing of S=O mesons in particular pions, as well was isospin symmetry v iolation, so only the rho a(1) contribution is considered in isobar ex citation. We find a significant contribution to A ($) over bar(L) from the PV mixing of the states P-3(2) and D-1(2) already at relatively l ow energies, versus one (vector) meson exchange which gives predominan tly P-3(o)-S-1(o) mixing. At the energy of 230 MeV, where a forthcomin g TRIUMF experiment aims to extract the parity violating rho pp coupli ng, our calculated effect from this source alone is of the same order as from the conventional single rho exchange.