Measurement of the bb¯ dijet cross section in pp collisions at √s=7 TeV with the ATLAS detector

Abstract

The dijet production cross section for jets containing a b-hadron (b-jets) has been measured in proton–proton collisions with a centre-of-mass energy of s=7 TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of 4.2fb-1. The cross section is measured for events with two identified b-jets with a transverse momentum pT> 20 GeV and a minimum separation in the η–ϕ plane of Δ R= 0.4. At least one of the jets in the event is required to have pT> 270 GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the b-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization.