K-S(0) and Lambda Production in Pb-Pb Collisions at root s(NN)=2: 76 TeV
ALICE Collaboration (ukupan broj autora: 943)
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The ALICE measurement of K-S(0) and Lambda production at midrapidity in Pb-Pb collisions at root sNN = 2.76 TeV is presented. The transverse momentum (p(T)) spectra are shown for several collision centrality intervals and in the p(T) range from 0: 4 GeV/c (0: 6 GeV/c for Lambda) to 12 GeV/c. The p(T) dependence of the Lambda/K-S(0) ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher p(T) with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate p(T) is not observed in pp interactions at root s = 0.9 TeV and at root s = 7 TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured p(T) spectra above 2 GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of p(T), models that incorporate the influence of th...e medium on the fragmentation and hadronization processes describe qualitatively the p(T) dependence of the Lambda/K-S(0) ratio.
Source:Physical Review Letters, 2013, 111, 22
- State Committee of Science, World Federation of Scientists (WFS), Swiss Fonds Kidagan, Armenia, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundacao de Amparo a Pesquisa do Estado de Sao 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 Republic, Danish Natural Science Research Council, Carlsberg Foundation, Danish National Research Foundation, European Research Council under the European Community, Helsinki Institute of Physics, Academy of Finland, French CNRS-IN2P3, CEA, France, German BMBF, Helmholtz AssociationGeneral Secretariat for Research and Technology, Ministry of Development, Greece, Hungarian OTKA, National Office for Research and Technology (NKTH), Department of Atomic Energy, Department of Science and Technology of the Government of India, Istituto Nazionale di Fisica Nucleare (INFN), Centro Fermi-Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Italy, MEXT, japan, Joint Institute for Nuclear Research, Dubna, National Research Foundation of Korea (NRF), CONACYT, DGAPA, ALFA-EC, EPLANET Program (European Particle Physics Latin American Network), Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Netherlands, Research Council of Norway (NFR), Polish Ministry of Science and Higher Education, National Authority for Scientific Research-NASR, Ministry of Education and Science of Russian Federation, Russian Academy of Sciences, Russian Federal Agency of Atomic Energy, Russian Federal Agency for Science and Innovations, Russian Foundation for Basic Research, Ministry of Education of Slovakia, Department of Science and Technology, South Africa, CIEMAT, EELA, Ministerio de Economia y Competitividad (MINECO) of Spain, Xunta de Galicia (Conselleria de Educacion), CEADEN, Cubaenergia, Cuba, IAEA (International Atomic Energy Agency), Swedish Research Council, Knut and Alice Wallenberg Foundation (KAW), Ukraine Ministry of Education and Science, United Kingdom Science and Technology Facilities Council (STFC), United States Department of Energy, United States National Science Foundation, State of Texas, State of Ohio