Charged jet cross section and fragmentation in proton-proton collisions at √s = 7 TeV

Abstract

We report the differential charged jet cross section and jet fragmentation distributions measured with the ALICE detector in proton-proton collisions at a center-of-mass energy √s = 7 TeV. Jets with pseudorapidity |η|<0.5 are reconstructed from charged particles using the anti-kT jet-finding algorithm with a resolution parameter R=0.4. The jet cross section is measured in the transverse momentum interval 5≤pTch jet<100 GeV/c. Jet fragmentation is studied measuring the scaled transverse momentum spectra of the charged constituents of jets in four intervals of jet transverse momentum between 5 and 30 GeV/c. The measurements are compared to calculations from the pythia model as well as next-to-leading-order perturbative QCD calculations with powheg+pythia8. The charged jet cross section is well described by powheg for the entire measured range of pTch jet. For pTch jet>40 GeV/c, the pythia calculations also agree with the measured charged jet cross section. pythia6 simulations describe the fragmentation distributions to 15%. Larger discrepancies are observed for pythia8.