Limit on nuclear time-reversal-invariance violation from the neutron electric dipole moment

Time-reversal noninvariance in nuclei has recently been parametrized in terms of a four-point coupling, of undetermined strength, of an isovector photon, a charged pion, and the nucleon current. If parity violation is introduced via the weak interaction, this coupling is restricted by the failure to observe a neutron electric dipole moment to a size which is an order of magnitude smaller than the limit imposed by present nuclear γ-decay experiments.