Charge-dependent two- and three-particle correlations measured in Xe–Xe collisions at √sNN = 5.44 TeV are
presented. Results are obtained for charged particles in the pseudorapidity range |η| < 0.8 and transverse
momentum interval 0.2 ≤ pT < 5.0 GeV/c for different collision centralities. The three-particle correlator γαβ ≡
⟨cos(φα +φβ −2Ψ2)⟩, calculated for different combinations of charge sign α and β, is expected to be sensitive to
the presence of the Chiral Magnetic Effect (CME). Its magnitude is similar to the one observed in Pb–Pb collisions
in contrast to a smaller CME signal in Xe–Xe collisions than in Pb–Pb collisions predicted by Monte Carlo (MC)
calculations including a magnetic field induced by the spectator protons. These observations point to a large non-
CME contribution to the correlator. Furthermore, the charge dependence of γαβ can be described by a blast wave
model calculation that incorporates background effects and by the Anomalous Viscous Fluid Dynamics model
with values of the CME signal consistent with zero. The Xe–Xe and Pb–Pb results are combined with the expected
CME signal dependence on the system size from the MC calculations including a magnetic field to obtain the
fraction of CME contribution in γαβ, fCME. The CME fraction is compatible with zero for the 30% most central
events in both systems and then becomes positive. This yields an upper limit of 2% (3%) and 25% (32%) at
95% (99.7%) confidence level for the CME signal contribution to γαβ in the 0–70% Xe–Xe and Pb–Pb collisions,
respectively.
