V−A constraint on a product of R-parity violating couplings

We study in the framework of R-parity violating supersymmetric theories the effect of R-parity violation due to the operator LiLjEk on the (V−A) structure of the muon decay. The precisely measured muon decay parameters can constrain a product of R-parity violating couplings: |λ232λ131|<0.022 at the 90% CL, which is complementary to the previous limits obtained by the e-μ universality in τ decay.