Enhanced tau lepton signatures at LHC in the constrained supersymmetric seesaw model

Abstract

We discuss the possible enhancement of the tau lepton events, with the emphasis on the signals with three or more hadronic taus, at LHC when the left-handed stau doublet becomes light or even lighter than the right-handed one. This is the natural outcome of the supersymmetric seesaw models where the slepton doublet mass is suppressed by the effects of a large neutrino Yukawa coupling. We study a few representative parameter sets in the sneutrino coannihilation regions where the tau sneutrino is next-to-lightest supersymmetric particle and the stau coannihilation regions where the stau is next-to-lightest supersymmetric particle both of which yield the thermal neutralinolightest supersymmetric particle abundance determined by Wilkinson Microwave Anisotropy Probe.