ProbingR-parity violating models of neutrino mass at the LHC via top squark decays

Abstract

We show that the R-parity violating decays of the lighter top squarks (t-tilde{sub 1}) triggered by the lepton number violating couplings {lambda}{sub i33}{sup '}, where the lepton family index i=1-3, can be observed at the LHC via the dilepton dijet channel even if the coupling is as small as 10{sup -4} or 10{sup -5}. This is the case in several models of neutrino mass, provided the t-tilde{sub 1} is the next lightest supersymmetric particle and the lightest neutralino is the lightest supersymmetric particle. First, we have obtained a fairly model-independent estimate of the minimum observable value of the parameter [P{sub ij}{identical_to}BR(t-tilde{yields}l{sub i}{sup +}b)xBR(t-tilde*{yields}l{sub j}{sup -}b)] at the LHC for an integrated luminosity of 10 fb{sup -1} as a function of m{sub t-tilde1} by a standard Pythia based analysis. We have then computed the parameter P{sub ij} in several representative models of neutrino mass constrained by the neutrino oscillation data and have found that the theoretical predictions are above the estimated minimum observable levels for a wide region of the parameter space.