Search for the pair production of light top squarks in the e+_ µ_+ final state in proton-proton collisions at √s = 13 TeV

• Autor(a) principal: Sirunyan, A. M.
• Data de Publicação: 2019
• Outros Autores: Silveira, Gustavo Gil da, CMS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/196338
• topic: Aceleradores de partículas; Colisões proton-proton; Supersimetrias; Hadron-Hadron scattering (experiments); Supersymmetry; Top squark

A search for the production of a pair of top squarks at the LHC is presented. This search targets a region of parameter space where the kinematics of top squark pair production and top quark pair production are very similar, because of the mass di erence between the top squark and the neutralino being close to the top quark mass. The search is performed with 35.9 fb1 of proton-proton collisions at a centre-of-mass energy of p s = 13TeV, collected by the CMS detector in 2016, using events containing one electron-muon pair with opposite charge. The search is based on a precise estimate of the top quark pair background, and the use of the MT2 variable, which combines the transverse mass of each lepton and the missing transverse momentum. No excess of events is found over the standard model predictions. Exclusion limits are placed at 95% con dence level on the production of top squarks up to masses of 208 GeV for models with a mass di erence between the top squark and the lightest neutralino close to that of the top quark.