Observation of Charge-Dependent Azimuthal Correlations in p-Pb Collisions and Its Implication for the Search for the Chiral Magnetic Effect


Khachatryan V., Sirunyan A. M. , Tumasyan A., Adam W., Asilar E., Bergauer T., ...More

PHYSICAL REVIEW LETTERS, vol.118, no.12, 2017 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 118 Issue: 12
  • Publication Date: 2017
  • Doi Number: 10.1103/physrevlett.118.122301
  • Title of Journal : PHYSICAL REVIEW LETTERS

Abstract

Charge-dependent azimuthal particle correlations with respect to the second-order event plane in p-Pb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range broken vertical bar eta broken vertical bar < 2.4, and a third particle measured in the hadron forward calorimeters (4.4 < broken vertical bar eta broken vertical bar < 5). The observed differences between the same and opposite sign correlations, as functions of multiplicity and. gap between the two charged particles, are of similar magnitude in p-Pb and PbPb collisions at the same multiplicities. These results pose a challenge for the interpretation of charge-dependent azimuthal correlations in heavy ion collisions in terms of the chiral magnetic effect.