Measurements of jet multiplicity and jet transverse momentum in multijet events in proton-proton collisions at √s=13 TeV

Multijet events at large transverse momentum (p _T) are measured at s=13TeV using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 36.3fb-1 . The multiplicity of jets with pT>50GeV that are produced in association with a high- p _T dijet system is measured in various ranges of the p _T of the jet with the highest transverse momentum and as a function of the azimuthal angle difference Δϕ _{1 , 2} between the two highest p _T jets in the dijet system. The differential production cross sections are measured as a function of the transverse momenta of the four highest p _T jets. The measurements are compared with leading and next-to-leading order matrix element calculations supplemented with simulations of parton shower, hadronization, and multiparton interactions. In addition, the measurements are compared with next-to-leading order matrix element calculations combined with transverse-momentum dependent parton densities and transverse-momentum dependent parton shower.