Abstract
Measurements of the differential cross sections for the production of exactly four jets in proton-proton collisions are presented as a function of the transverse momentum pt and pseudorapidity eta, together with the correlations in azimuthal angle and the pt balance among the jets. The data sample was collected in 2010 at a center-of-mass energy of 7 TeV with the CMS detector at the LHC, with an integrated luminosity of 36 inverse picobarns. The cross section for a final state with a pair of hard jets with pt > 50 GeV and another pair with pt > 20 GeV within abs(eta) < 4.7 is measured to be sigma = 330 +- 5 (stat.) +- 45 (syst.) nb. It is found that fixed-order matrix element calculations including parton showers describe the measured differential cross sections in some regions of phase space only, and that adding contributions from double parton scattering brings the Monte Carlo predictions closer to the data.
Highlights
The production of jets with large transverse momenta in high-energy proton-proton collisions can be described within the theory of strong interactions, QCD, by the scattering of partons
The inclusive cross section for high-pT jets has been measured by the ATLAS [1] and Compact Muon Solenoid (CMS) [2] Collaborations and is in good agreement with predictions obtained at next-toleading order (NLO) in perturbative QCD
It has been verified at stable-particle level with the distributions investigated here that the differences between the predictions obtained with MADGRAPH and SHERPA are due to the different contributions coming from multiparton interactions” (MPI), while the predictions agree with each other if MPI are switched off
Summary
The production of jets with large transverse momenta (pT) in high-energy proton-proton collisions can be described within the theory of strong interactions, QCD, by the scattering of partons. The inclusive cross section for high-pT jets has been measured by the ATLAS [1] and Compact Muon Solenoid (CMS) [2] Collaborations and is in good agreement with predictions obtained at next-toleading order (NLO) in perturbative QCD. The ATLAS Collaboration has measured high-pT multijet cross sections [3] and obtained good agreement with NLO calculations [4,5]. The hard scattering process produces two or more partons at high pT, with the initial- and finalstate QCD radiation resulting in additional jets at lower pT. This partonic process, coming from single parton scattering (SPS), is a crucial test for higher-order QCD calculations, as well as for the description of high-pT jets within the parton shower (PS) formalism
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.