Measurement of charge multiplicity asymmetry correlations in high-energy nucleus-nucleus collisions at √s[subscript NN] = 200 GeV

• Main Authors: Betancourt, Michael Joseph (Contributor), Corliss, Ross (Contributor), Hays-Wehle, James Prewitt (Contributor), Leight, William Axel (Contributor), Redwine, Robert P. (Contributor), Seele, J. (Contributor), Steadman, Stephen G. (Contributor), van Nieuwenhuizen, Gerrit Jan (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2014-08-21T12:55:30Z.
• Subjects: Article
• Online Access: Get fulltext

 A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au + Au collisions at √s[subscript NN] = 200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, Δ, between the like- and unlike-sign up/down-left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic v[obs over 2]), where Δ = [1.3 ± 1.4(stat)[+4.0 over −1.0](syst)] × 10[superscript −5] + [3.2 ± 0.2(stat)[+0.4 over −0.3](syst)] × 10[superscript −3]v[obs over 2] for 20-40% Au + Au collisions. The implications for the proposed chiral magnetic effect are discussed.