Search for long-lived particles using out-of-time trackless jets in proton-proton collisions at √s = 13 TeV

• Autor(a) principal: Tumasyan, Armen
• Data de Publicação: 2023
• Outros Autores: Silveira, Gustavo Gil da, Bernardes, César Augusto, CMS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/270335
• topic: Aceleradores de partículas; Bosons de higgs; Colisões proton-proton; Beyond Standard Model; Hadron-Hadron scattering

A search for long-lived particles decaying in the outer regions of the CMS silicon tracker or in the calorimeters is presented. The search is based on a data sample of proton-proton collisions at √ s = 13 TeV recorded with the CMS detector at the LHC in 2016–2018, corresponding to an integrated luminosity of 138 fb−1 . A novel technique, using nearly trackless and out-of-time jet information combined in a deep neural network discriminator, is employed to identify decays of long-lived particles. The results are interpreted in a simplified model of chargino-neutralino production, where the neutralino is the next-to-lightest supersymmetric particle, is long-lived, and decays to a gravitino and either a Higgs or Z boson. This search is most sensitive to neutralino proper decay lengths of approximately 0.5 m, for which masses up to 1.18 TeV are excluded at 95% confidence level. The current search is the best result to date in the mass range from the kinematic limit imposed by the Higgs boson mass up to 1.8 TeV.