R-b and R-l in MSSM without R-parity

摘要: We examined Zb (b) over bar and Zl (l) over bar couplings in the minimal supersymmetric model with explicit trilinear R-parity violating interactions. We found that the top quark couplings lambda (i3k)' and lambda (3j3)" can give sizable contributions through top quark loops. When deriving the bounds from R-b and R-l data, we also take into account the loop contributions of R-parity conserving interactions. The bounds from R-l are found to be stronger than those from R-b and serve as the hitherto strongest bounds for some couplings.