Expressions for the P,T-violating NN potentials are derived for π, ρ, and ω exchange. The nuclear matrix elements for ρ and ω exchange are shown to be greatly suppressed, so that, under the assumption of comparable coupling constants, π exchange would dominate by two orders of magnitude. The ratio of P,T-violating to P-violating matrix elements is found to remain approximately constant across the nuclear mass table, thus establishing the proportionality between time-reversal-violation and parity-violation matrix elements. The calculated values of this ratio suggest a need to obtain an accuracy of order 5×${10}^{\mathrm{-}4}$ for the ratio of the PT-violating to P-violating asymmetries in neutron transmission experiments in order to improve on the present limits on the isovector pion coupling constant.

• Received 23 September 1993

DOI:https://doi.org/10.1103/PhysRevC.49.2391