Constraints on R-parity violating couplings from CERN LEP and SLAG SLD hadronic observables

Abstract

We analyze the one loop corrections to hadronic Z decays in an R–parity violating extension to the Minimal Supersymmetric Standard Model (MSSM). Performing a global fit to all the hadronic observables at the Z–peak, we obtain stringent constraints on the R–violating coupling constants λ′ and λ′′ . The presence of these couplings worsens the agreement with the data relative to the Standard Model. The strongest constraints come from the b asymmetry parameters Ab and AFB ( b). From a classical statistical analysis we find that the couplings λ′i31, λ′i32, and λ ′′321 are ruled out at the 1σ level, and that λ′i33 and λ′′33i are ruled out at the 2σ level. We also obtain Bayesian confidence limits for the R–violating couplings.