Measurements of top-quark pair differential cross-sections in the eμ channel in pp collisions at √s=13 TeV using the ATLAS detector

• Autor(a) principal: Santos, S. P. Amor dos
• Data de Publicação: 2017
• Outros Autores: Carvalho, J., Fiolhais, M. C. N., Galhardo, B., Veloso, F., Wolters, H., ATLAS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/108170; https://doi.org/10.1140/epjc/s10052-017-4821-x

This article presents measurements of t ¯t differential cross-sections in a fiducial phase-space region, using an integrated luminosity of 3.2 fb−1 of proton–proton data at a centre-of-mass energy of √ s = 13 TeV recorded by the ATLAS experiment at the LHC in 2015. Differential crosssections are measured as a function of the transverse momentum and absolute rapidity of the top quark, and of the transverse momentum, absolute rapidity and invariant mass of the t ¯t system. The t ¯t events are selected by requiring one electron and onemuonof opposite electric charge, and at least two jets, one of which must be tagged as containing a b-hadron. The measured differential cross-sections are compared to predictions of next-to-leading order generators matched to parton showers and the measurements are found to be consistent with all models within the experimental uncertainties with the exception of the Powheg-Box + Herwig++ predictions, which differ significantly from the data in both the transverse momentum of the top quark and the mass of the t ¯t system.