Constraints on R-parity violating couplings from LEP/SLD hadronic observables

TL;DR

This paper investigates how one-loop corrections in an R-parity violating MSSM extension affect hadronic Z decays, leading to stringent constraints on certain R-violating couplings based on LEP/SLD data.

Contribution

It provides the first comprehensive global fit to hadronic Z decay observables constraining R-violating couplings in the MSSM.

Findings

Certain R-violating couplings are ruled out at 1 sigma and 2 sigma levels.

Strong constraints are derived from b asymmetry parameters A_b and A_FB(b).

Bayesian confidence limits for the couplings are established.

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 couplings constants lambda' and lambda''. As a result of the strong constraints from the b asymmetry parameters A_b and A_FB(b), we find that the couplings lambda'{i31}, lambda'{i32}, and lambda''{321} are ruled out at the 1 sigma level, and that lambda'{i33} and lambda''{33i} are ruled out at the 2 sigma level. We also obtain Bayesian confidence limits for the R-violating couplings.