Influence of globally spin-aligned vector mesons to the measurements of the chiral magnetic effect in heavy-ion collisions

Abstract

The chiral magnetic effect (CME) in high-energy heavy-ion collisions arises from the interplay between the chirality imbalance and the intense magnetic field and will cause a charge separation along the magnetic field direction. While the CME search is still ongoing in experiments, the non-CME contributions need to be excluded from the CME observables. In this work, we examine the influence of globally spin-aligned ρ mesons on the γ112 correlator, the RΨ2(ΔS) correlator, and the signed balance functions, via a toy model and a multiphase transport model (AMPT). We find that the CME observables are sensitive to the 00-component of the spin density matrix, ρ00: they receive positive (negative) contributions when ρ00 is larger (smaller) than 1/3.