Determine the magnetic-field contribution to hyperon global polarization

Determine whether the initial magnetic field contributes to the global polarization of hyperons in heavy-ion collisions, producing a splitting between the global polarizations of Lambda and anti-Lambda because of their opposite magnetic moments.

Background

Global hyperon polarization is generally interpreted as arising from vorticity in the matter produced by a non-central heavy-ion collision. A magnetic-field contribution would generate opposite polarization effects for particles and antiparticles because Lambda and anti-Lambda have opposite magnetic moments. The paper notes that Beam Energy Scan phase-II measurements found no significant difference between the two polarizations and consequently placed an upper limit on the late-stage magnetic field, but whether an initial magnetic field contributes remains unresolved.