Same-sign trilepton signal for a stop in presence of sneutrino LSP

25 Jul 2018, 14:50
Room A

Room A


Dr Subhadeep Mondal (University of Helsinki)


We have explored a minimal supersymmetric Standard Model scenario extended by one pair of gauge singlets per generation, where light neutrino masses and mixing are generated via inverse seesaw mechanism. In such a scenario, a right-handed sneutrino can be the lightest supersymmetric particle and a cold Dark Matter (DM) candidate. We have studied the constraints on such a scenario arising from non-observation lepton flavor violating (LFV) decays and DM data. We have observed that if the Dirac neutrino Yukawa coupling matrix is used to fit the neutrino oscillation data by Casas-Ibarra parametrisation, the resulting off-diagonal matrix is highly constrained from the LFV data. The resultant Yukawa parameter(s), also responsible for the sneutrino DM couplings, produces a very small direct detection cross-section lying orders of magnitude below the present XENON limit. However, the smallness of the Yukawa parameters also requires the sneutrino DM to co-annihilate with other sparticle(s) in order to satisfy DM relic density constraints. We have studied sneutrino co-annihilation with wino and observed that this sneutrino-wino compressed parameter space gives rise to a novel same-sign trilepton signal for the stop quark in this scenario.

Parallel Session Supersymmetry: Models, Phenomenology and Experimental Results

Primary author

Dr Subhadeep Mondal (University of Helsinki)


Prof. DILIP KUMAR GHOSH (INDIAN ASSOCIATION FOR THE CULTIVATION OF SCIENCE) Dr Manimala Mitra (Institute of Physics (IOP)) Prof. Katri Huitu (University of Helsinki)

Presentation materials