2026/07/16 by Ying Shan Zhao, Yifeng Sun
#nucl-th
Relativistic heavy-ion collisions provide a unique opportunity to probe ground-state nuclear structure through its imprint on the initial collision geometry. We investigate how multiparticle observables respond to combined variations of quadrupole deformation, triaxiality, and hexadecapole deformation, using 129Xe+129Xe collisions as a representative testing ground. We perform a joint analysis in the three-dimensional (β2,γ,β4) parameter space and construct initial-state estimators for several flow and mean transverse momentum correlation observables. At the initial-state level, ρ2 is primarily sensitive to β2 and γ, with its sensitivity to γ enhanced at nonzero β2. The nonlinear response coefficient χ4,22 is predominantly sensitive to β4, while its dependence on β2 and γ remains comparatively weak. Higher-order correlators exhibit more complex multidimensional response patterns; in particular, ρ224 shows a dependence on γ and β4 that becomes more pronounced at finite β2. We further employ the iEBE-VISHNU hybrid model to examine whether these deformation sensitivities survive the subsequent dynamical evolution. The final-state calculations indicate that the sensitivity of ρ2 to β2 and γ is largely preserved, whereas the β4 sensitivity of χ4,22 is substantially reduced. For the other higher-order observables, the initial-state sensitivities are modified by the evolution or cannot be resolved with the present statistics.