Observation of charge-dependent azimuthal correlations and possible local strong parity violation in heavy-ion collisions

Scientific paper - Original scientific paper

• Author: B. I. Abelev
• Author: ...
• Author: Mirko Planinić
• Author: ...
• Author: Nikola Poljak
• Author: ...
• Author: J. X. Zuo
• Collaboration: STAR Collaboration
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Parity (P)-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the orbital momentum of the system created in noncentral collisions. To study this effect, we investigate a three-particle mixed-harmonics azimuthal correlator which is a P-even observable, but directly sensitive to the charge-separation effect. We report measurements of this observable using the STAR detector in Au+Au and Cu+Cu collisions at √sNN=200 and 62 GeV. The results are presented as a function of collision centrality, particle separation in rapidity, and particle transverse momentum. A signal consistent with several of the theoretical expectations is detected in all four data sets. We compare our results to the predictions of existing event generators and discuss in detail possible contributions from other effects that are not related to P violation.

• Keywords (english): parity; violation heavy ion; scattering gold copper quantum chromodynamics; vacuum state correlation function; (3particle) charged particle; angular correlation topological Monte Carlo STAR Brookhaven RHIC Coll impact parameter; dependence rapidity dependence transverse momentum; dependence 62; 200 GeV-cms/nucleon
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C - Nuclear Physics
• Numbering: vol. 81, no. 5, 054908
• p-ISSN: 0556-2813
• e-ISSN: 1089-490X
• DOI: https://doi.org/10.1103/PhysRevC.81.054908
• URN:NBN: urn:nbn:hr:217:350194
• Publication: 2010
• Project: Number: 119-0982887-1006; Title (croatian): Istraživanje hadronskih sustava upotrebom relativističkih projektila; Leader: Mirko Planinić; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: http://link.aps.org/doi/10.1103/PhysRevC.81.054908
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2010) by the American Physical Society. Received 10 September 2009; published 28 May 2010.
• Created on: 2019-11-02 17:48:53