Bounds on $\Delta B=1$ Couplings in the Supersymmetric Standard Model

Abstract

The most general supersymmetric model contains baryon number violating terms of the form ${\lambda }_{ijk}\text{ov}{D}_i\text{ov}{D}_j\text{ov}{U}_k$ in the superpotential. We reconsider the bounds on these couplings, assuming that lepton number conservation ensures proton stability. These operators can mediate $n-\text{ov}n$ oscillations and double nucleon decay. We show that neutron oscillations do not, as previously claimed, constrain the ${\lambda }_{dsu}$ coupling; they do provide a bound on the ${\lambda }_{dbu}$ coupling, which we calculate. We find that the best bound on ${\lambda }_{dsu}$ 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.

Comments: Latex, four figures in eps. 16 pages