Assessing background effects in search of the chiral vortical effect in relativistic heavy-ion collisions

The search for the Chiral Vortical Effect (CVE) in relativistic heavy-ion collisions is carried out by measuring azimuthal correlators for baryon pairs such as Λ and protons. Experimental results from the ALICE collaboration show significant separations in these correlator observables between baryon-baryon and baryon-antibaryon, however, the interpretation remains unclear. It is believed that background contributions from baryon production mechanisms play an important role. Using three phenomenological models, the Blast Wave, AMPT, and AVFD+UrQMD, we systematically investigate the background effects in Pb–Pb collisions at s N N = 5.02 TeV. We demonstrate that local baryon conservation, as well as hadronic annihilation processes, can significantly influence the correlators. The feed-down contribution from secondary protons is also estimated. Our study provides a foundation for disentangling background mechanisms and further facilitates the search for the CVE.