6 research outputs found
D-meson production in p-Pb collisions at root S-NN=5.02 TeV and in pp collisions at root S=7 TeV
Peer reviewe
Correlated Event-by-Event Fluctuations of Flow Harmonics in Pb-Pb Collisions at root S-NN=2.76 TeV
Peer reviewe
Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p-Pb collisions root S-NN=5.02 TeV
The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity (-0.5 10 GeV/c), the particle ratios are consistent with those reported for pp and Pb-Pb collisions at the LHC energies. At intermediate p(T) the (anti)proton R-ppb shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high p(T) the charged pion, kaon and (anti)proton R-ppb are consistent with unity within statistical and systematic uncertainties. (C) 2016 The Author. Published by Elsevier B.V.Peer reviewe
Direct photon production in Pb-Pb collisions at \sqrt{s_\rm{NN}} = 2.76 TeV
25 pages, 6 captioned figures, 2 tables, authors from page 20, submitted to PLB, figures at http://aliceinfo.cern.ch/ArtSubmission/node/1887 ; see paper for full list of authorsInternational audienceDirect photon production at mid-rapidity in Pb-Pb collisions at TeV was studied in the transverse momentum range GeV. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the ALICE detector material with the pair reconstructed in the central tracking system. The results of the two methods were combined and direct photon spectra were measured for the 0-20%, 20-40%, and 40-80% centrality classes. For all three classes, agreement was found with perturbative QCD calculations for GeV. Direct photon spectra down to GeV could be extracted for the 20-40% and 0-20% centrality classes. The significance of the direct photon signal for GeV is for the 0-20% class. The spectrum in this range and centrality class can be described by an exponential with an inverse slope parameter of MeV. State-of-the-art models for photon production in heavy-ion collisions agree with the data within uncertainties
Jet-like correlations with neutral pion triggers in pp and central Pb-Pb collisions at 2.76 TeV
26 pages, 5 captioned figures, 1 table, authors from page 19, submitted to PLB, figures at http://aliceinfo.cern.ch/ArtSubmission/node/3021, see paper for full list of authorsInternational audienceWe present measurements of two-particle correlations with neutral pion trigger particles of transverse momenta , while with decreasing momenta an enhancement develops reaching about at low . On the near side, an enhancement of between at the highest to at the lowest is observed. The data are compared to parton-energy-loss predictions of the JEWEL and AMPT event generators, as well as to a perturbative QCD calculation with medium-modified fragmentation functions. All calculations qualitatively describe the away-side suppression at high . Only AMPT captures the enhancement at low , both on the near and away side. However, it also underpredicts above GeV/, in particular on the near-side
Search for weakly decaying (Lambda n)over-bar and Lambda Lambda exotic bound states in central Pb-Pb collisions at root S-NN=2.76 TeV
We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible (Lambda n) over bar bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at root S-NN = 2.76 TeV, by invariant mass analysis in the decay modes (Lambda n) over bar (d) over bar pi(+) and H-dibaryon -> Lambda p pi(-). No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V