Studies of inclusive four-jet production with two b-tagged jets in proton-proton collisions at 7 TeV

TL;DR

This paper reports measurements of the cross section for producing at least four jets with two originating from b quarks in proton-proton collisions at 7 TeV, comparing results with advanced QCD-based event generators.

Contribution

First measurement of four-jet production with two b-tagged jets at 7 TeV, providing data to test and refine QCD models and event generators.

Findings

Measured inclusive cross section: 69 +/- 3 (stat) +/- 24 (syst) nb.

Jet distributions and correlations are well modeled by NLO QCD with parton showers.

Data supports current QCD models for multi-jet production with b quarks.

Abstract

Measurements are presented of the cross section for the production of at least four jets, of which at least two originate from b quarks, in proton-proton collisions. Data collected with the CMS detector at the LHC at a center-of-mass energy of 7 TeV are used, corresponding to an integrated luminosity of 3 inverse picobarns. The cross section is measured as a function of the jet transverse momentum for pt > 20 GeV, and of the jet pseudorapidity for abs(eta) < 2.4 (b jets), 4.7 (untagged jets). The correlations in azimuthal angle and pt between the jets are also studied. The inclusive cross section is measured to be sigma(pp to 2 b + 2 j + X) = 69 +/- 3 (stat) +/- 24 (syst) nb. The eta and pt distributions of the four jets and the correlations between them are well reproduced by event generators that combine perturbative QCD calculations at next-to-leading-order accuracy with contributions from parton showers and multiparton interactions.