Abstract
The differential production cross sections of B^{±} mesons are measured via the exclusive decay channels B^{±}→J/ψK^{±}→μ^{+}μ^{-}K^{±} as a function of transverse momentum in pp and Pb-Pb collisions at a center-of-mass energy sqrt[s_{NN}]=5.02 TeV per nucleon pair with the CMS detector at the LHC. The pp(Pb-Pb) data set used for this analysis corresponds to an integrated luminosity of 28.0 pb^{-1} (351 μb^{-1}). The measurement is performed in the B^{±} meson transverse momentum range of 7 to 50 GeV/c, in the rapidity interval |y|<2.4. In this kinematic range, a strong suppression of the production cross section by about a factor of 2 is observed in the Pb-Pb system in comparison to the expectation from pp reference data. These results are found to be roughly compatible with theoretical calculations incorporating beauty quark diffusion and energy loss in a quark-gluon plasma.
Highlights
BofÆ-m→asJs =eψneKrgÆy→pffisμffiffiNþffiffiNffiμffi −1⁄4K5Æ.0a2s a function of transverse momentum TeV per nucleon pair with the CMS in pp and detector at
A strong suppression of the production cross section by about a factor of 2 is observed in the Pb-Pb system in comparison to the expectation from pp reference data. These results are found to be roughly compatible with theoretical calculations incorporating beauty quark diffusion and energy loss in a quark-gluon plasma
A state consisting of deconfined quarks and gluons, the quark-gluon plasma (QGP) [1,2], is predicted by lattice quantum chromodynamics (QCD) calculations [3]
Summary
Over wide pT and rapidity (y) intervals, and in proton-lead (ppffiPffiffiffibffiffi)ffi sNN collisions at a 1⁄4 5.02 TeV center-of-mass energy per nucleon [23]. Several Monte Carlo (MC) simulated event samples are used to evaluate background components, signal efficiencies and detector acceptance corrections This includes samples containing only the BÆ meson decays channels being measured, and samples with inclusive (prompt and nonprompt) J=ψ mesons. The Pb-Pb collision event is required to have at least three towers in each of the HF detectors with energy deposits of more than 3 GeV per tower These criteria select ð99 Æ 2Þ% of inelastic hadronic Pb-Pb collisions. Two muons of opposite charge with an invariant mass within 150 MeV=c2 of the worldaverage J=ψ meson mass [25] are selected to reconstruct a J=ψ candidate, with a mass resolution of typically 18–55 MeV=c2, degrading as a function of the dimuon rapidity and pT. The differential cross section for BÆ production in jyj < 2.4 is computed in each pT interval according to dσBÆ dpT jyj
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
