Search for direct pair production of supersymmetric partners to the τ lepton in proton–proton collisions at √s=13TeV

Abstract

A search is presented for ττ slepton pairs produced in proton–proton collisions at a center-of-mass energy of 13TeVTeV. The search is carried out in events containing two ττ leptons in the final state, on the assumption that each ττ slepton decays primarily to a ττ lepton and a neutralino. Events are considered in which each ττ lepton decays to one or more hadrons and a neutrino, or in which one of the ττ leptons decays instead to an electron or a muon and two neutrinos. The data, collected with the CMS detector in 2016 and 2017, correspond to an integrated luminosity of 77.2fb−1fb−1. The observed data are consistent with the standard model background expectation. The results are used to set 95% confidence level upper limits on the cross section for ττ slepton pair production in various models for ττ slepton masses between 90 and 200GeVGeV and neutralino masses of 1, 10, and 20GeVGeV. In the case of purely left-handed ττ slepton production and decay to a ττ lepton and a neutralino with a mass of 1GeVGeV, the strongest limit is obtained for a ττ slepton mass of 125GeVGeV at a factor of 1.14 larger than the theoretical cross section.