Transverse momentum spectra of b jets in pPb collisions at sqrt(s[NN]) = 5.02 TeV

CMS [UCL] Basegmez, Suzan [UCL] Beluffi, Camille [UCL] Bondu, Olivier [UCL] Brochet, Sébastien [UCL] Bruno, Giacomo [UCL] Castello, Roberto [UCL] Caudron, Adrien [UCL] Ceard, Ludivine [UCL] Da Silveira, Gustavo Gil [UCL] Delaere, Christophe [UCL] Favart, Denis [UCL] Forthomme, Laurent [UCL] Giammanco, Andrea [UCL] Hollar, Jonathan [UCL] Jafari, Abideh [UCL] Jez, Pavel [UCL] Komm, Matthias [UCL] Lemaitre, Vincent [UCL] Mertens, Alexandre [UCL] Nuttens, Claude [UCL] Perrini, Lucia [UCL] Pin, Arnaud [UCL] Piotrzkowski, Krzysztof [UCL] Popov, Andrey [UCL] Quertenmont, Loic [UCL] Selvaggi, Michele [UCL] Vidal Maroño, Miguel [UCL] et al.

We present a measurement of b jet transverse momentum (pt) spectra in proton-lead (pPb) collisions using a dataset corresponding to about 35 inverse nanobarns collected with the CMS detector at the LHC. Jets from b quark fragmentation are found by exploiting the long lifetime of hadrons containing a b quark through tagging methods using distributions of the secondary vertex mass and displacement. Extracted cross sections for b jets are scaled by the effective number of nucleon-nucleon collisions and are compared to a reference obtained from PYTHIA simulations of pp collisions. The PYTHIA-based estimate of the nuclear modification factor is found to be 1.22 +/- 0.15 (stat + syst pPb) +/- 0.27 (syst PYTHIA) averaged over all jets with pt between 55 and 400 GeV/c and with abs(eta[lab]) < 2. We also compare this result to predictions from models using perturbative calculations in quantum chromodynamics.