Measurement of inclusive charged-particle b-jet production in pp and p-Pb collisions at root S-NN =5.02 TeV

A measurement of the inclusive b-jet production cross section is presented in pp and p-Pb collisions at root S-NN = 5.02 TeV, using data collected with the ALICE detector at the LHC. The jets were reconstructed in the central rapidity region vertical bar eta vertical bar < 0.5 from charged particles using the anti-kT algorithm with resolution parameter R = 0.4. Identification of b jets exploits the long lifetime of b hadrons, using the properties of secondary vertices and impact parameter distributions. The p(T)-differential inclusive production cross section of b jets, as well as the corresponding inclusive b-jet fraction, are reported for pp and p-Pb collisions in the jet transverse momentum range 10 <= p(T)(,)(ch)( jet) <= 100 GeV/c, together with the nuclear modification factor, R-pPb(b-jet). The analysis thus extends the lower p(T) limit of b-jet measurements at the LHC. The nuclear modification factor is found to be consistent with unity, indicating that the production of b jets in p-Pb at root S-NN = 5.02 TeV is not affected by cold nuclear matter effects within the current precision. The measurements are well reproduced by POWHEG NLO pQCD calculations with PYTHIA fragmentation.