清涼飮料税論

The production of J/\).psi\) and $\psi(2S)$ was measured with the ALICE detector in Pb-Pb collisions at the LHC. The measurement was performed at forward rapidity 2.5 < y < 4 \() down to zero transverse momentum \(p_{\rm T} in the dimuon decay channel. Inclusive J/\).psi\) yields were extracted in different centrality classes and the centrality dependence of the average $p_{\rm T}$ is presented. The J/\).psi\) suppression, quantified with the nuclear modification factor $R_{\rm AA}$ , was studied as a function of centrality, transverse momentum and rapidity. Comparisons with similar measurements at lower collision energy and theoretical models indicate that the J/\).psi\) production is the result of an interplay between color screening and recombination mechanisms in a deconfined partonic medium, or at its hadronization. Results on the $\psi(2S)$ suppression are provided via the ratio of $\psi(2S)$ over J/\).psi\) measured in pp and Pb-Pb collisions

Multiplicity dependence of pion, kaon, proton and lambda production in p–Pb collisions at √sNN = 5.02 TeV

Inthis Letter, comprehensive results on π±,K±,K0S, p(pbar) and Λ(Λbar) production at mid-rapidity (0< yCMS < 0.5) in p–Pb collisions at √sNN = 5.02 TeV, measured by the ALICE detector at the LHC, are reported. The transverse momentum distributions exhibit a hardening as a function of event multiplicity, which is stronger for heavier particles. This behavior is similar to what has been observed in pp and Pb–Pb collisions at the LHC. The measured pT distributions are compared to d–Au, Au–Au and Pb–Pb results at lower energy and with predictions based on QCD-inspired and hydrodynamic models

Production of charged pions, kaons and protons at large transverse momenta in pp and Pb-Pb collisions at root s(NN)=2.76 TeV

Transverse momentum spectra of pi(+/-), K-+/- and p((p) over bar) up to p(T) = 20 GeV/c at mid-rapidity in pp, peripheral (60-80%) and central (0-5%) Pb-Pb collisions at v root s(NN) = 2.76 TeV have been measured using the ALICE detector at the Large Hadron Collider. The proton-to-pion and the kaon-to-pionratios both show a distinct peak at p(T) approximate to 3 GeV/c in central Pb-Pb collisions. Below the peak, p(T) 10 GeV/c particle ratios in pp and Pb-Pb collisions are in agreement and the nuclear modification factors for pi(+/-), K-+/- and p((p) over bar) indicate that, within the systematic and statistical uncertainties, the suppression is the same. This suggests that the chemical composition of leading particles from jets in the medium is similar to that of vacuum jets. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY licens

D Meson Elliptic Flow in Noncentral Pb-Pb Collisions at root(S)(NN)=2.76 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Azimuthally anisotropic distributions of D-0, D+, and D*+ mesons were studied in the central rapidity region (vertical bar y vertical bar < 0.8) in Pb-Pb collisions at a center-of-mass energy root(S)(NN) = 2.76 TeV per nucleon-nucleon collision, with the ALICE detector at the LHC. The second Fourier coefficient upsilon(2) (commonly denoted elliptic flow) was measured in the centrality class 30%-50% as a function of the D meson transverse momentum p(T), in the range 2-16 GeV/c. The measured upsilon(2) of D mesons is comparable in magnitude to that of light-flavor hadrons. It is positive in the range 2 < p(T) < 6 GeV/c with 5.7 sigma significance, based on the combination of statistical and systematic uncertainties.11110State Committee of ScienceWorld Federation of Scientists (WFS)Swiss Fonds Kidagan, ArmeniaConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Financiadora de Estudos e Projetos (FINEP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)National Natural Science Foundation of China (NSFC)Chinese Ministry of Education (CMOE)Ministry of Science and Technology of China (MSTC)Ministry of Education and Youth of the Czech RepublicDanish Natural Science Research CouncilCarlsberg FoundationDanish National Research FoundationEuropean Research Council under the European CommunityHelsinki Institute of PhysicsAcademy of FinlandFrench CNRS-IN2P3, FranceRegion Pays de Loire, FranceRegion Alsace, FranceRegion Auvergne, FranceCEA, FranceGerman BMBFHelmholtz AssociationGeneral Secretariat for Research and Technology, Ministry of Development, GreeceHungarian OTKANational Office for Research and Technology (NKTH)Department of Atomic EnergyDepartment of Science and Technology of the Government of IndiaIstituto Nazionale di Fisica Nucleare (INFN)Centro Fermi-Museo Storico della Fisica e Centro Studi e Ricerche 'Enrico Fermi,' ItalyMEXT, JapanJoint Institute for Nuclear Research, DubnaNational Research Foundation of Korea (NRF)CONACYT, MexicoDGAPA, MexicoALFA-ECEPLANET Program (European Particle Physics Latin American Network) Stichting voor Fundamenteel Onderzoek der Materie (FOM), NetherlandsNederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), NetherlandsResearch Council of Norway (NFR)Polish Ministry of Science and Higher EducationNational Authority for Scientific Research-NASR (Autoritatea Nationala pentru Cercetare Stiintifica-ANCS)Ministry of Education and Science of Russian FederationRussian Academy of SciencesRussian Federal Agency of Atomic EnergyRussian Federal Agency for Science and InnovationsRussian Foundation for Basic ResearchMinistry of Education of SlovakiaDepartment of Science and Technology, South AfricaCIEMATEELAMinisterio de Economia y Competitividad (MINECO) of SpainXunta de Galicia (Conselleria de Educacion)CEADENCubaenergiaCubaIAEA (International Atomic Energy Agency)Swedish Research Council (VR)Knut & Alice Wallenberg Foundation (KAW)Ukraine Ministry of Education and ScienceUnited Kingdom Science and Technology Facilities Council (STFC)United States Department of EnergyUnited States National Science FoundationState of TexasState of OhioConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Exclusive J/psi Photoproduction off Protons in Ultraperipheral p-Pb Collisions at root s(NN)=5.02 TeV

We present the first measurement at the LHC of exclusive J/psi photoproduction off protons, in ultraperipheral proton-lead collisions at root s(NN) = 5.02 TeV. Events are selected with a dimuon pair produced either in the rapidity interval, in the laboratory frame, 2.5 J/psi + p) are 33.2 +/- 2.2(stat) +/- 3.2(syst) +/- 0.7(theor) nb in p-Pb and 284 +/- 36(stat)(-32)(+27)(syst) +/- 26(theor) nb in Pb-p collisions. We measure this process up to about 700 GeV in the gamma p center of mass, which is a factor of two larger than the highest energy studied at HERA. The data are consistent with a power law dependence of the J/psi photoproduction cross section in gamma p energies from about 20 to 700 GeV, or equivalently, from Bjorken x scaling variable between similar to 2 x 10(-2) and similar to 2 x 10(-5), thus indicating no significant change in the gluon density behavior of the proton between HERA and LHC energies

Multiplicity dependence of the average transverse momentum in pp, p-Pb, and Pb-Pb collisions at the LHC

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The average transverse momentum (p(T)) versus the charged-particle multiplicity N-ch was measured in p-Pb collisions at a collision energy per nucleon-nucleon root S-NN = 5.02 TeV and in pp collisions at collision energies of root s = 0.9, 2.76, and 7 TeV in the kinematic range 0.15 < p(T) < 10.0 GeV/c and vertical bar eta vertical bar < 0.3 with the ALICE apparatus at the LHC. These data are compared to results in Pb-Pb collisions at root S-NN = 2.76 TeV at similar charged-particle multiplicities. In pp and p-Pb collisions, a strong increase of (p(T)) with N-ch is observed, which is much stronger than that measured in Pb-Pb collisions. For pp collisions, this could be attributed, within a model of hadronizing strings, to multiple-parton interactions and to a final-state color reconnection mechanism. The data in p-Pb and Pb-Pb collisions cannot be described by an incoherent superposition of nucleon-nucleon collisions and pose a challenge to most of the event generators. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.72741763371380State Committee of ScienceWorld Federation of Scientists (WFS)Swiss Fonds Kidagan, ArmeniaConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Financiadora de Estudos e Projetos (FINEP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)National Natural Science Foundation of China (NSFC)Chinese Ministry of Education (CMOE)Ministry of Science and Technology of China (MSTC)Ministry of Education and Youth of the Czech RepublicDanish Natural Science Research CouncilCarlsberg FoundationDanish National Research FoundationEuropean Research Council under European Community's Seventh Framework ProgrammeHelsinki Institute of PhysicsAcademy of FinlandFrench [CNRS-IN2P3]Region Pays de LoireRegion AlsaceRegion AuvergneCEA, FranceGerman BMBFHelmholtz AssociationGeneral Secretariat for Research and TechnologyMinistry of Development, GreeceHungarian OTKANational Office for Research and Technology (NKTH)Department of Atomic EnergyDepartment of Science and Technology of the Government of IndiIstituto Nazionale di Fisica Nucleare (INFN)Centro Fermi Museo Storico della Fisica e Centro Studi e Ricerche 'Enrico Fermi', ItalySpecially Promoted Research, JapanJoint Institute for Nuclear Research, DubnaNational Research Foundation of Korea (NRF)Stichting voor Fundamenteel Onderzoek der Materie (FOM)Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), NetherlandsResearch Council of Norway (NFR)Polish Ministry of Science and Higher EducationNational Authority for Scientific Research - NASRAutoritatea Nationala pentru Cercetare Stiintifica - ANCSMinistry of Education and Science of Russian FederationRussian Academy of SciencesRussian Federal Agency of Atomic EnergyRussian Federal Agency for Science and InnovationsRussian Foundation for Basic ResearchMinistry of Education of SlovakiaDepartment of Science and Technology, South AfricaCIEMATEELAMinisterio de Economia y Competitividad (MINECO) of SpainXunta de Galicia (Conselleria de Educacion)CEADENCubaenergiaCubaIAEA (International Atomic Energy Agency)Swedish Research Council (VR)Knut & Alice Wallenberg Foundation (KAW)Ukraine Ministry of Education and ScienceUnited Kingdom Science and Technology Facilities Council (STFC)United States Department of EnergyUnited States National Science FoundationState of TexasState of OhioConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)French [CNRS-IN2P3

Long-range angular correlations of pi, K and p in p-Pb collisions at root s(NN)=5.02 TeV

Angular correlations between unidentified charged trigger particles and various species of charged associated particles (unidentified particles, pions, kaons, protons and antiprotons) are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV in the transverse-momentum range 0.3 < p(T) < 4 GeV/c. The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range vertical bar n(lab)vertical bar < 0.8. Fourier coefficients are extracted from the long-range correlations projected onto the azimuthal angle difference and studied as a function of p(T) and in intervals of event multiplicity. In high-multiplicity events, the second-order coefficient for protons, 4, is observed to be smaller than that for pions, v(2)(pi), up to about p(T) = 2 GeV/c. To reduce correlations due to jets, the per-trigger yield measured in low-multiplicity events is subtracted from that in high-multiplicity events. A two-ridge structure is obtained for all particle species. The Fourier decomposition of this structure shows that the second-order coefficients for pions and kaons are similar. The v(2)(p) is found to be smaller at low P-T and larger at higher p(T) than v(2)(pi), with a crossing occurring at about 2 GeV/c. This is qualitatively similar to the elliptic-flow pattern observed in heavy-ion collisions. A mass ordering effect at low transverse momenta is consistent with expectations from hydrodynamic model calculations assuming a collectively expanding system. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.7264169916417

J/ψ elliptic flow in Pb-Pb collisions at √s NN =2.76 TeV

We report on the first measurement of inclusive J/psi elliptic flow v(2) in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at root s(NN) = 2.76 TeV in the rapidity range 2.5 < y < 4.0. The dependence of the J/psi v(2) on the collision centrality and on the J/psi transverse momentum is studied in the range 0 <= p(T) < 10 GeV/c. For semicentral Pb-Pb collisions at root s(NN) = 2.76 TeV, an indication of nonzero v(2) is observed with a largest measured value of v(2) = 0.116 +/-0.046(stat) +/- 0.029(syst) for J/psi in the transverse momentum range 2 <= p(T) < 4 GeV/c. The elliptic flow measurement complements the previously reported ALICE results on the inclusive J/psi nuclear modification factor and favors the scenario of a significant fraction of J/psi production from charm quarks in a deconfined partonic phase