Lightest-Neutralino Decays in Rp-violating Models with Dominant ?' and ? Couplings

Decays of the lightest neutralino are studied in R_p-violating models with operators $\lambda^{\prime}LQD^c$ and $\lambda LLE^c$ involving third-generation matter fields and with dominant $\lambda^{\prime}$ and lambda couplings. Generalizations to decays of the lightest neutralino induced by subdominant $\lambda^{\prime}$ and lambda couplings are straightforward. Decays with the top-quark among the particles produced are considered, in addition to those with an almost massless final state. Phenomenological analyses for examples of both classes of decays are presented. No specific assumption on the composition of the lightest neutralino is made, and the formulae listed here can be easily generalized to study decays of heavier neutralinos. It has been recently pointed out that, for a sizable coupling $\lambda^{\prime}_{333}$, tau-sleptons may be copiously produced at the LHC as single supersymmetric particles, in association with top- and bottom-quark pairs. This analysis of neutralino decays is, therefore, a first step towards the reconstruction of the complete final state produced in this case.