1,977 research outputs found
Heavy-flavor suppression and azimuthal anisotropy in Pb-Pb collisions at sqrt(s_{NN}) = 2.76 TeV with the ALICE detector
Heavy-flavor hadron production studies in Pb-Pb collisions at sqrt(s_{NN}) =
2.76 TeV with the 2010 and 2011 data samples are presented. The measurements
are performed with the ALICE detector in various decay channels and in a wide
kinematic range. Heavy-flavor hadrons exhibit a suppression in the most central
Pb-Pb collisions that amounts to a factor 3-5 for pT ~ 8-10 GeV/c. The second
harmonic of the azimuthal distribution Fourier decomposition, v2, is non-zero
for non-central collisions at intermediate pT (~3 GeV/c).Comment: Quark Matter 2012 proceeding
Open Heavy Flavor Production in p-p and Pb-Pb collisions as seen by ALICE at the LHC
Charm and beauty production are probed with the ALICE experiment at the LHC
by studying the single lepton transverse momentum distribution (electrons at
mid-rapidity, muons at large-rapidities) and D mesons reconstructed in their
hadronic decays. The differential production cross sections in proton proton
interactions show a good agreement with perturbative QCD calculations at both
sqrt(s) = 2.76 and 7 TeV. The measurements in lead lead reactions at
sqrt(s_{NN})= 2.76 TeV evidence a reduction (or suppression) of the production
rate at intermediate and high pt in the most central collisions with respect to
the rate in proton proton interactions.Comment: To appear in the Proceedings of the 19th Particles and Nuclei
International Conference, PANIC 201
Electroweak boson detection in the ALICE muon spectrometer
The ALICE capabilities for W and Z detection at LHC are discussed. The contributions to single muon transverse momentum distribution are evaluated. The expected performance of the muon spectrometer for detecting W and Z bosons via their muonic decay is presented. Possible application for the study of in-medium effects in ultrarelativistic heavy ion collisions is discussed.The ALICE capabilities for W and Z detection at LHC are discussed. The contributions to single muon transverse momentum distribution are evaluated. The expected performance of the muon spectrometer for detecting W and Z bosons via their muonic decay is presented. Possible application for the study of in-medium effects in ultrarelativistic heavy ion collisions is discussed
Open-beauty production in Pb collisions at =5 TeV: effect of the gluon nuclear densities
We present our results on open beauty production in proton-nucleus collisions
for the recent LHC Pb run at =5 TeV. We have analysed the
effect of the modification of the gluon PDFs in nucleus at the level of the
nuclear modification factor. Because of the absence of measurement in
collisions at the same energy, we also propose the study of the
forward-to-backward yield ratio in which the unknown proton-proton yield
cancel. Our results are compared with the data obtained by LHCb collaboration
and show a good agreement.Comment: 6 pages, 3 figures, Proceedings IS2013 submitted to Nuclear Physics
Phenomenological interpolation of the inclusive J/psi cross section to proton-proton collisions at 2.76 TeV and 5.5 TeV
We present a study of the inclusive J/psi cross section at 2.76 TeV and 5.5
TeV. The energy dependence of the cross section, rapidity and transverse
momentum distributions are evaluated phenomenologically. Their knowledge is
crucial as a reference for the interpretation of A-A and p-A J/psi results at
the LHC. Our approach is the following: first, we estimate the energy evolution
of the pt-integrated J/psi cross section at mid-rapidity; then, we evaluate the
rapidity dependence; finally, we study the transverse momentum distribution
trend. Whenever possible, both theory driven (based on pQCD predictions) and
functional form (data driven fits) calculations are discussed. Our predictions
are compared with the recently obtained results by the ALICE collaboration in
pp collisions at 2.76 TeV.Comment: 23 pages, 19 figures, updated text+figures, added comparison to ALICE
measurements at 2.76Te
Vector bosons in heavy-ion collisions at the LHC
Vector bosons become accessible experimental probes in heavy-ion collisions
at the LHC. The capabilities of the LHC experiments to perform their
measurement are outlined. The focus is given to their utility to study the
possible formation and properties of the Quark Gluon Plasma (QGP) in the most
central heavy-ion collisions. Their own sensitivity (if any) to the QGP is
discussed. Their interest as references to observe multiple QGP sensitive
probes is justified.Comment: HP2008 proceedings, to appear in Eur.Phys.J.
Effect of heavy-quark energy loss on the muon differential production cross section in Pb-Pb collisions at \sqrtsNN=5.5 TeV
We study the nuclear modification factors RAA and RCP of the high transverse
momentum 5<pt<60 GeV/c distribution of muons in Pb--Pb collisions at LHC
energies. We consider two pseudo-rapidity ranges covered by the LHC
experiments: and . Muons from semi-leptonic decays of
heavy quarks (c and b) and from leptonic decays of weak gauge bosons (W and Z)
are the main contributions to the muon pt distribution above a few GeV/c. We
compute the heavy quark contributions using available pQCD-based programs. We
include the nuclear shadowing modification of the parton distribution functions
and the in-medium radiative energy loss for heavy quarks, using the
mass-dependent BDMPS quenching weights. Muons from W and Z leptonic decays,
that dominate the yield at high pt, can be used as a medium-blind reference to
observe the medium-induced suppression of beauty quarks
Z0 Boson Measurement with the ALICE Central Barrel in pp collisions at 14 TeV
The possibility to detect the Z0 in the ALICE central barrel is studied via
the electronic decay channel Z0->e+e-. The signal and the background are
simulated with the leading order event generator PYTHIA 6. The total
cross-sections are taken from NLO calculations. Based on test beam data, the
electron identification performance of the Transition Radiation Detector is
extrapolated to high momenta. The expected yields for minimum-bias pp
collisions at 14 TeV are presented. An isolation cut on the single electron,
together with a minimum transverse momentum cut, allows to obtain a clear
signal. The expected background is of the order of 1 % with the main
contribution coming from misidentified pions from jets.Comment: 4 pages, 3 figures, QM2008 proceeding
D meson nuclear modification factors in Pb-Pb collisions at {\surd}sNN = 2.76 TeV, measured with the ALICE detector
The ALICE experiment has measured the D meson production in pp and Pb-Pb
collisions at the LHC at {\surd}s = 7 and 2.76 TeV and {\surd}sNN = 2.76 TeV
respectively, via the exclusive reconstruction of hadronic decay channels. The
analyses of the D0{\to}K-pi+ and D+{\to}K-pi+pi+ channels will be described and
the preliminary results for the D0 and D+ nuclear modification factor will be
presented.Comment: Proceedings of Quark Matter 2011 conference. 4 pages, 4 figures. The
slides of the talk can be found at the link:
http://indico.cern.ch/materialDisplay.py?contribId=591&sessionId=53&materialId=slides&confId=3024
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