Implications of Horizontal Symmetries on Baryon Number Violation in   Supersymmetric Models
  The smallness of the quark and lepton parameters and the hierarchy between them could be the result of selection rules due to a horizontal symmetry broken by a small parameter. The same selection rules apply to baryon number violating terms. Consequently, the problem of baryon number violation in Supersymmetry may be solved naturally, without invoking any especially-designed extra symmetry. This mechanism is efficient enough even for low-scale flavor physics. Proton decay is likely to be dominated by the modes $K^+\bar\nu_i$ or $K^0\mu^+(e^+)$, and may proceed at observable rates. 
Valerie Ben-Hamo and Yosef Nir