Búsqueda de materia oscura en asociación con pares de quark top en el experimento cms

Résumé

This thesis deals with a search of dark matter produced in association with tt pairs in data from proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC. The data corresponds to 35.9 inverse femtobarns collected with the CMS detector in 2016. The analysis looks for an excess of events with large imbalance in transverse momentum and a top quark pair decaying in the dileptonic mode. The results are interpreted in the context of simplified models of dark matter production. Assuming unitary coupling values to standard model (SM) particles gq, and dark matter (DM) particles gc, and DM mass mc = 1 GeV, the observed (expected) 95% CL exclusions for a scalar mediator are mf < 73 (84) GeV, while no exclusion is expected or observed at 95% CL for the pseudoscalar mediators.