Jet Production and QCD at High Energy Colliders

Abstract

Selected quantum chromodynamics (QCD) measurements performed at the Fermilab Run II Tevatron p ¯ p collider ( √ s = 1.96 TeV) by CDF and D0 collaborations, at the LHC pp collider ( √ s = 7 and 8 TeV) by CMS and ATLAS collaborations, and at HERAe ± p collider ( √ s = 300 and 314 GeV) by H1 and ZEUS collaborations are presented. The inclusive jet, dijet production and threejet cross section measurements are used to test perturbativ e QCD calculations, constrain parton distribution function determinations, and extract values of the strong coupling constant. Events with W/Z+jets production are used to measure many kinematic distributions allowing extensive testing and tuning predictions from next-to-leading-orde r (NLO) perturbative QCD (pQCD) and Monte-Carlo event generators. The diphoton production cross-sections check the validity of the NLO pQCD predictions, soft-gluon resummation methods implemented in theoretical calculations, and contributions from the parton-to-photon fragme ntation diagrams. The photon+b-jet cross-section measurements reveal an inability of NLO perturbative pQCD calculations to describe spectrum at high transverse momentum. Events with inclusive production of vector boson (γ/W/Z) and ≥ 2 jets are used to study increasingly important phenomenon of multiple parton interactions, measure an effective interaction cross sect ion, and limit existing models.