Measurements of t¯t cross sections in association with b jets and inclusive jets and their ratio using dilepton final states in pp collisions at √s=13TeV

Abstract

The cross sections for the production of t¯tb¯b and t¯tjj events and their ratio σt¯tb¯b/σt¯tjj are measured using data corresponding to an integrated luminosity of 2.3 fb−1collected in pp collisions at √s=13TeV with the CMS detector at the LHC. Events with two leptons (e or μ) and at least four reconstructed jets, including at least two identified as b quark jets, in the final state are selected. In the full phase space, the measured ratio is 0.022±0.003(stat)±0.006(syst), the cross section σt¯tb¯b is 4.0±0.6(stat)±1.3(syst)pb and σt¯tjj is 184±6(stat)±33(syst)pb. The measurements are compared with the standard model expectations obtained from a powheg simulation at next-to-leading-order interfaced with pythia.