Bounds on ΔB = 1 couplings in the supersymmetric standard model

The most general supersymmetric model contains baryon number violating terms of the form λijk, DiDjUk in the superpotential. We reconsider the bounds on these couplings, assuming that lepton number conservation ensures proton stability. These operators can mediate n - n oscillations and double nucleon decay. We show that neutron oscillations do not, as previously claimed, constrain the λdsu coupling; they do provide a bound on the λdbu coupling, which we calculate. We find that the best bound on λdsu arises from double nucleon decay into two kaons; the calculation is discussed in detail. There are no published limits on this process; experimenters are urged to examine this nuclear decay mode. Finally, the other couplings can be bounded by the requirement of perturbative unification.