P,T-violating nuclear matrix elements in the one-meson exchange approximation

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^-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.