Upper bound on all products of R-parity violating couplings $λ'$ and $λ''$ from proton decay

Abstract

We prove that {\em any} product of R-parity violating couplings $λ&#39;$ (L-violating) and $λ&#39;&#39;$ (B-violating) can be strongly restricted by proton decay data. For any pair $λ&#39;$ and $λ&#39;&#39;$ the decay exists at least at one loop level. For squark masses below 1 TeV we find the conservative bounds $|λ&#39; \cdot λ&#39;&#39;| < 10^{-9}$ in absence of squark flavor mixing, and $|λ&#39; \cdot λ&#39;&#39;| < 10^{-11}$ when this mixing is taken into account. We study the dependence of the bounds on the flavor basis in which R-parity breaking couplings are determined.