The inclusive transverse momentum (pT) distributions of primary charged particles are measured in the pseudo-rapidity range |η|<0.8 as a function of event centrality in Pb–Pb collisions at sNN=2.76 TeV with ALICE at the LHC. The data are presented in the pT range 0.15<pT<50 GeV/c for nine centrality intervals from 70–80% to 0–5%. The results in Pb–Pb are presented in terms of the nuclear modification factor RAA using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-pT particles strongly depends on event centrality. The yield is most suppressed in central collisions (0–5%) with RAA≈0.13 at pT=6–7 GeV/c. Above pT=7 GeV/c, there is a significant rise in the nuclear modification factor, which reaches RAA≈0.4 for pT>30 GeV/c. In peripheral collisions (70–80%), only moderate suppression (RAA=0.6–0.7) and a weak pT dependence is observed. The measured nuclear modification factors are compared to other measurements and model calculations.
|Number of pages||11|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2013 Mar 13|
Bibliographical noteFunding Information:
The ALICE Collaboration acknowledges the following funding agencies for their support in building and running the ALICE detector: Calouste Gulbenkian Foundation from Lisbon and Swiss Fonds Kidagan , Armenia; Conselho 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) , the Chinese Ministry of Education (CMOE) and the Ministry of Science and Technology of China (MSTC) ; Ministry of Education and Youth of the Czech Republic ; Danish Natural Science Research Council , the Carlsberg Foundation and the Danish National Research Foundation ; The European Research Council under the European Communityʼs Seventh Framework Programme ; Helsinki Institute of Physics and the Academy of Finland ; French CNRS-IN2P3 , the ‘Region Pays de Loire’ , ‘Region Alsace’ , ‘Region Auvergne’ and CEA , France; German BMBF and the Helmholtz Association ; General Secretariat for Research and Technology, Ministry of Development , Greece; Hungarian OTKA and National Office for Research and Technology (NKTH) ; Department of Atomic Energy and Department of Science and Technology of the Government of India ; Istituto Nazionale di Fisica Nucleare (INFN) of Italy ; MEXT Grant-in-Aid for Specially Promoted Research , Japan; Joint Institute for Nuclear Research , Dubna; National Research Foundation of Korea (NRF) ; CONACYT , DGAPA , México, ALFA-EC and the HELEN Program (High-Energy physics Latin-American–European Network) ; Stichting voor Fundamenteel Onderzoek der Materie (FOM) and the 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 (Autoritatea Naţională pentru Cercetare Ştiinţifică — ANCS) ; Federal Agency of Science of the Ministry of Education and Science of Russian Federation , International Science and Technology Center , Russian Academy of Sciences , Russian Federal Agency of Atomic Energy , Russian Federal Agency for Science and Innovations and CERN-INTAS ; Ministry of Education of Slovakia ; Department of Science and Technology , South Africa; CIEMAT , EELA , Ministerio de Educación y Ciencia of Spain , Xunta de Galicia (Consellería de Educación) , CEADEN, Cubaenergía , Cuba, and IAEA (International Atomic Energy Agency) ; Swedish Research Council (VR) and Knut & Alice Wallenberg Foundation (KAW) ; Ukraine Ministry of Education and Science ; United Kingdom Science and Technology Facilities Council (STFC) ; The United States Department of Energy , the United States National Science Foundation , the State of Texas , and the State of Ohio .
© 2013 CERN
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics