Probing the chiral magnetic wave in pPb and PbPb collisions at sNN =5.02 TeV using charge-dependent azimuthal anisotropies
Journal
Physical Review C
Journal Volume
100
Journal Issue
6
Date Issued
2019
Author(s)
Abstract
Charge-dependent anisotropy Fourier coefficients (v n ) of particle azimuthal distributions are measured in pPb and PbPb collisions at s NN = 5.02 TeV with the CMS detector at the LHC. The normalized difference in the second-order anisotropy coefficients (v 2 ) between positively and negatively charged particles is found to depend linearly on the observed event charge asymmetry with comparable slopes for both pPb and PbPb collisions over a wide range of charged particle multiplicity. In PbPb, the third-order anisotropy coefficient v 3 shows a similar linear dependence with the same slope as seen for v 2 . The observed similarities between the v 2 slopes for pPb and PbPb, as well as the similar slopes for v 2 and v 3 in PbPb, are compatible with expectations based on local charge conservation in the decay of clusters or resonances, and constitute a challenge to the hypothesis that, at LHC energies, the observed charge asymmetry dependence of v 2 in heavy ion collisions arises from a chiral magnetic wave.
SDGs
Type
journal article