Speaker
Description
Relativistic heavy-ion collisions offer a unique opportunity to probe the deformation of colliding nuclei. The quadrupole deformation parameter ($\beta_2$) has been extensively studied through the flow coefficient $v_2$ in such collisions, as well as through low-energy measurements of the electric quadrupole transition probabilities, B(E2). In contrast, the hexadecapole deformation ($\beta_4$) has often been neglected in modeling heavy-ion collisions, primarily due to large experimental and theoretical uncertainties. In this poster, we present measurements of the non-linear response coefficient between $v_4$ and $v_2$, ($\chi_{4,22}$), in Au+Au and U+U collisions at $\sqrt{s_{NN}}$ = 200 GeV and 193 GeV, respectively. A deviation from 1 of the ratio of $\chi_{4,22}$ between U+U and Au+Au collisions would suggest sizeable hexadecapole deformation in Uranium-238. These results will be compared with iEBE-VISHNU hydrodynamic and AMPT model studies, which incorporate the $\beta_4$ value of Uranium-238 from nuclear structure theory calculations.
| Category | Experiment |
|---|---|
| Collaboration (if applicable) | STAR collaboration |
