Speaker
Description
We investigate the influence of nuclear structure on transverse spherocity ($S_0$) distributions in $^{238}U+^{238}U$ collisions at $\sqrt{S_{NN}}=193$ GeV. The initial spatial anisotropy of colliding nuclei is expected to imprint distinct signatures on final-state event topology. Hydrodynamic evolution translates these initial geometric anisotropies into momentum-space correlation via collective flow. $S_0$ integrates over these correlations, making it a sensitive probe of both initial geometry and nuclear structure.
Our results demonstrate a strong dependence of $S_0$ on the quadrupole deformation $\beta_2$, with larger deformations shifting the distribution toward more anisotropic (jet-like) events. In contrast, no significant effects are observed for triaxiality ($\gamma$), octupole ($\beta_3$), and hexadecapole ($\beta_4$)deformations when using the standard $S_0$ definition. However, by isolating $p_T$ fluctuations through $\delta p_T=(p_T-\langle p_T\rangle)/\langle p_T\rangle$ and $\delta p_T^2$, we uncover subtle but systematic variations in distribution for different and values. These results demonstrate that while $\beta_2$ dominantly modulates global event isotropy, higher-order deformations ($\beta_3, \beta_4$) manifest only when $S_0$ is generalized to incorporate $p_T$-fluctuation-driven observables. These findings establish a new connection between initial-state nuclear structure and final-state momentum anisotropies. We propose this fluctuation-sensitive $S_0$ as a novel tool for heavy-ion experiments to constrain nuclear deformation parameters through event-shape engineering, complementing traditional flow measurements.
