Charge correlations using the balance function in Pb-Pb collisions at √sNN=2.76 TeV

ALICE Collaboration

Research output: Contribution to journalArticlepeer-review

56 Scopus citations

Abstract

In high-energy heavy-ion collisions, the correlations between the emitted particles can be used as a probe to gain insight into the charge creation mechanisms. In this Letter, we report the first results of such studies using the electric charge balance function in the relative pseudorapidity (d?) and azimuthal angle (df) in Pb-Pb collisions at sNN=2.76 TeV with the ALICE detector at the Large Hadron Collider. The width of the balance function decreases with growing centrality (i.e. for more central collisions) in both projections. This centrality dependence is not reproduced by HIJING, while AMPT, a model which incorporates strings and parton rescattering, exhibits qualitative agreement with the measured correlations in df but fails to describe the correlations in d?. A thermal blast-wave model incorporating local charge conservation and tuned to describe the pTspectra and v2measurements reported by ALICE, is used to fit the centrality dependence of the width of the balance function and to extract the average separation of balancing charges at freeze-out. The comparison of our results with measurements at lower energies reveals an ordering with sNN: the balance functions become narrower with increasing energy for all centralities. This is consistent with the effect of larger radial flow at the LHC energies but also with the late stage creation scenario of balancing charges. However, the relative decrease of the balance function widths in d? and df with centrality from the highest SPS to the LHC energy exhibits only small differences. This observation cannot be interpreted solely within the framework where the majority of the charge is produced at a later stage in the evolution of the heavy-ion collision.

Original languageEnglish
Pages (from-to)267-279
Number of pages13
JournalPhysics Letters B
Volume723
Issue number4-5
DOIs
StatePublished - Jun 25 2013
Externally publishedYes

Funding

The ALICE Collaboration acknowledges the following funding agencies for their support in building and running the ALICE detector: State Committee of Science , 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) and Centro Fermi – Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi” , Italy; MEXT Grant-in-Aid for Specially Promoted Research , Japan; Joint Institute for Nuclear Research , Dubna; National Research Foundation of Korea (NRF) ; CONACYT , DGAPA , Mexico, 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) ; 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 .

Keywords

  • ALICE LHC
  • Balance function
  • Charge correlations

Fingerprint

Dive into the research topics of 'Charge correlations using the balance function in Pb-Pb collisions at √sNN=2.76 TeV'. Together they form a unique fingerprint.

Cite this