Imaging the structure of atomic nuclei in high-energy nuclear collisions from STAR experiment

Abstract

In relativistic heavy-ion collisions, the extractions of properties of quark-gluon plasma (QGP) are hindered by a limited understanding of its initial conditions, where the nuclear structure of the colliding ions plays a significant role. In these proceedings, we present the first quantitative demonstration using “collective flow assisted nuclear shape imaging” method to extract the quadrupole deformation and triaxiality from ²³⁸U using data from the Relativistic Heavy Ion Collider (RHIC). We achieve this by comparing bulk observables in collisions of highly deformed ²³⁸U and nearly spherical ¹⁹⁷Au. A similar comparative measurement performed in collisions of ⁹⁶Ru+⁹⁶Ru and ⁹⁶Zr+⁹⁶Zr, suggests the presence of moderate quadrupole deformation of ⁹⁶Ru, large octupole deformation of ⁹⁶Zr, as well as an apparent neutron skin difference between these two species. The prospect of this nuclear shape imaging method as a novel tool for the study of nuclear structure is also elaborated.