First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at sqrt(s) = 13TeVстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 27 октября 2021 г.
Аннотация:The first measurement of the inclusive cross section for top quark pairs (tt¯) produced in association with two additional charm jets is presented. The analysis uses the dileptonic final states of tt¯ events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 41.5 fb−1, recorded by the CMS experiment at the LHC. A new charm jet identification algorithm provides input to a neural network that is trained to distinguish among tt¯ events with two additional charm (tt¯cc¯), bottom (tt¯bb¯), and light-flavour or gluon (tt¯LL) jets. By means of a template fitting procedure, the inclusive tt¯cc¯, tt¯bb¯, and tt¯LL cross sections are simultaneously measured, together with their ratios to the inclusive tt¯ + two jets cross section. This provides measurements of the tt¯cc¯ and tt¯bb¯ cross sections of 10.1 ± 1.2 (stat) ± 1.4 (syst) pb and 4.54 ± 0.35 (stat) ± 0.56 (syst) pb, respectively, in the full phase space. The results are compared and found to be consistent with predictions from two different matrix element generators with next-to-leading order accuracy in quantum chromodynamics, interfaced with a parton shower simulation.