2017/09/17 by Jacopo Margutti, Margutti, Jacopo
Physics and Astronomy · #FOS: Physical sciences #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · doi:10.48550/arxiv.1709.05618
openalex publication_date 2017/09/17 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
In non-central heavy-ion collisions unprecedented strong magnetic fields, of the order of 1018 Gauss, are expected to be produced. The interplay of such fields with QCD anomalies in the Quark--Gluon Plasma (QGP) has been predicted to lead to a number of interesting phenomena, such as the Chiral Magnetic Effect (CME). While several experimental observations are partially consistent with predictions of a CME signal, it is hard to distinguish them unambiguously from a combination of more mundane phenomena present in the anisotropic expansion of the QGP. This makes it imperative to establish that the early-time magnetic field has observable consequences not related to the anomalous QCD effects on final-state charged particles and to calibrate its strength. We test a recent prediction of a pure electromagnetic effect, which may arise in heavy-ion collisions. The varying magnetic field would induce a current within the QGP, which is expected to leave a very peculiar imprint on final-state particles: a contribution to directed flow which is asymmetric both in charge and pseudorapidity. We report the measurement of the charge dependence of directed flow with respect to the spectator plane for unidentified charged particles in Pb--Pb collisions at √(sNN) = 5.02 TeV.