2025/08/26 by Deng, X. G., Ma, Y. G.
#FOS: Physical sciences #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.2508.19105
We report a novel manifestation of spin-vorticity interplay in relativistic heavy-ion collisions. Using 16O+197Au at √s\rm NN=7.7 GeV as a test case, we show that the Λ hyperon exhibits a clear dual-polarization structure, observed here in central 16O + 197Au collisions for the first time. The polarization is further highly sensitive to the intrinsic nuclear geometry: different α-cluster configurations of 16O, ranging from chain-like to tetrahedral, lead to distinct polarization patterns across centralities. In particular, the backward rapidity region and peripheral events display striking structure-dependent variations, including opposite angular distributions of local polarizations Px and Py compared with a spherical reference. These findings reveal that nuclear clustering leaves measurable imprints on hyperon spin alignment in relativistic collisions. Our results open a promising avenue for probing nuclear structure in short-lived systems and highlight a new spin-sensitive mechanism relevant for upcoming experiments at RHIC and future facilities.