Charged jet cross section and fragmentation in proton-proton collisions at root S=7 TeV

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 root S = 7 TeV. Jets with pseudorapidity vertical bar eta vertical bar < 0.5 are reconstructed from charged particles using the anti-k(T) jet-finding algorithm with a resolution parameter R = 0.4. The jet cross section is measured in the transverse momentum interval 5 <= p(T)(ch 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 p(T)(ch jet). For p(T)(ch 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.