Measurement of the Ratio of the 3-jet to 2-jet Cross Sections in pp Collisions at sqrt(s) = 7 TeV

TL;DR

This paper measures the ratio of 3-jet to 2-jet cross sections in proton-proton collisions at 7 TeV, comparing data with QCD models over a previously unexplored HT range, providing new insights into multijet production.

Contribution

It presents the first measurement of the 3-jet to 2-jet cross section ratio as a function of HT up to 2.5 TeV at 7 TeV, extending the experimental data into new energy territory.

Findings

All models agree with data for HT > 0.5 TeV.

Measurement extends the HT range for multijet studies.

Data helps validate QCD predictions at high energies.

Abstract

A measurement of the ratio of the inclusive 3-jet to 2-jet cross sections as a function of the total jet transverse momentum, HT, in the range 0.2 < HT < 2.5 TeV is presented. The data have been collected at a proton-proton centre-of-mass energy of 7 TeV with the CMS detector at the LHC, and correspond to an integrated luminosity of 36 inverse picobarns. Comparisons are made between the data and the predictions of different QCD-based Monte Carlo models for multijet production. All models considered in this study are consistent with the data for HT > 0.5 TeV. This measurement extends to an HT range that has not been explored before.