B meson nuclear modification factor in Pb–Pb at 5.02 TeV with CMS

Abstract

The study of beauty production in heavy-ion collisions is considered one of the key measurement to address the flavour-dependence of in-medium energy loss in PbPb collisions. In pPb collisions, studies of b-quark production can also provide insights into the relevance of cold nuclear matter effects in the heavy-flavour sector. The CMS experiment has excellent capabilities for measuring b-quark production thanks to the excellent performances of its muon and tracker system. In this talk, we will present the measurement of nuclear modification factors for fully reconstructed B mesons in pPb, and for the first time, pp and PbPb collisions at 5.02 TeV, as a function of transverse momentum. Presented at HardProbes2016 The 8th International Conference on Hard and Electromagnetic Probes of High-energy Nuclear CollisionsNuclear and Particle Physics Proceedings 00 (2016) 1-4 Nuclear and Particle Physics ProceedingsTa-Wei Wang on behalf of the CMS collaboration AbstractThe study of beauty production in heavy-ion collisions is considered to be one of the key measurement to address the flavour-dependence of in-medium energy loss in PbPb collisions. The Compact Muon Solenoid (CMS) experiment has excellent capabilities for measuring b-quark production thanks to the excellent performances of its muon and tracker system. In this talk, the measurement of nuclear modification factor of fully reconstructed B mesons for the first time in pp and PbPb collisions at 5.02 TeV as a function of transverse momentum will be presented.

Heavy Quark Energy Loss in the Quark-Gluon Plasma in the Moller theory

“…where I is the multiplicity of the heavy quark, θ = m/E is the dead cone angle, m is the heavy quark mass, ω and k t are the frequency and the transverse momenta of the radiated gluon, and E is the energy of the heavy quark. They resulting heavy quark quenching rate is then significantly smaller than the one observed in the experiment, where up to rather small energies of order several masses of heavy quark, the jet quenching rates of the heavy and light/massless quarks are the same [8,9].…”

Heavy quark radiation in the quark–gluon plasma in the Moliere theory: angular distribution of the radiation

“…where m is the mass of the radiating heavy quark, E is the heavy quark energy, θ = m/E and k t , ω are the transverse momenta and the energy of the radiated gluon. This effect however was found to be in a disagreement with the experimental data that shows that quenching weights for heavy and light quark are very close up to rather small jet energies of [25][26][27][28][29][30][31][32][33][34][35] GeV [12,13]. This contradiction led to an extensive research on the heavy quark radiation in the quark gluon plasma.…”

Heavy quark energy loss in the quark-gluon plasma in the Moller theory

“…rates of the heavy and light/massless quarks are the same [8,9]. However it was found in [10,11] (see also [12][13][14][15] for related research) that the dead cone effect is actually absent, both in the harmonic oscillator (HO) approximation to the BDMPSZ approach and in the first N = 1 term in the GLV opacity expansion [16][17][18].…”