We report measurements of the directed flow (v1) for charged kaons, ϕ mesons, and K*0 resonances in Au+Au collisions at √sNN = 14.5, 19.6, and 27 GeV. This analysis includes the first-ever v1 measurement for the K*0 resonance in heavy-ion collisions. Our results reveal a centrality-dependent difference in directed flow between charged kaons and K*0 resonances, with the difference increasing towards more central collisions. In contrast, the v1 difference between kaons and ϕ mesons remains nearly constant across centralities. The observed kaon-K*0 difference can be qualitatively understood within a hydrodynamic framework that incorporates a hadronic afterburner and an asymmetric loss of K*0 yields with respect to first order event plane. Since hadronic rescattering depends strongly on the system size and scattering cross sections among hadrons, the measured K*0 v1 offers valuable constraints on phase-space-dependent rescattering effects in heavy-ion collisions, thereby providing important input for transport-based models of QCD matter.
Md Nasini (Fri,) studied this question.