Same-Sign Dilepton Excesses and Light Top Squarks

Abstract: Run 1 data of the Large Hadron Collider (LHC) contain excessive events in the same-sign dilepton channel with b-jets and missing transverse energy (MET), which were observed by five separate analyses from ATLAS and CMS collaborations. We show that these events could be explained by direct production of top squarks (stops) in supersymmetry. In particular, a right-handed stop with a mass of 550 GeV decaying into 2 t quarks, 2 W bosons, and MET could fit the observed excess without being constrained by other direct search limits from Run 1. We propose kinematic cuts at 13 TeV to enhance the stop signal, and estimate that stops could be discovered with 40 inverse fb of integrated luminosity at Run 2 of the LHC, when considering only the statistical uncertainty.