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

Abstract

It is shown that the R-parity violating decays of the lighter top squarks (${\tilde{t}}_1$) triggered by the lepton number violating couplings ${\lambda }_{i33}^{\prime }$, where the lepton family index i = 1-3, can be observed at the LHC via the dilepton di-jet channel even if the coupling is as small as 10${}^{-4}$ or 10${}^{-5}$, which is the case in several models of neutrino mass, provided it is the next lightest supersymmetric particle(NLSP) the lightest neutralino being the lightest supersymmetric particle(LSP). We have first obtained a fairly model independent estimate of the minimum observable value of the parameter ($P_{ij}\equiv BR(\tilde{t}\to l_i^{+}b)\times BR({\tilde{t}}^{\ast }\to l_j^{-}\bar{b}$)) at the LHC for an integrated luminosity of 10fb${}^{-1}$ as a function of $\text{mlstop}$ by a standard Pythia based analysis. We have then computed the parameter $P_{ij}$ 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.

Comments: 19 pages, 1 Figure and 11 Tables