High Energy / Nuclear Theory / RIKEN Seminars

[Hybrid RBRC seminar] Imaging the structure of atomic nuclei with high energy nuclear collisions

by Chunjian Zhang (Stony Brook University)

2-160 (https://bnl.zoomgov.com/j/1619458475?pwd=Z1VDdXVXcWF1eUhsRDZObVJnME4rUT09)




Atomic nuclei exhibit a wide range of emergent phenomena of the many-body quantum system across the nuclide landscape, including nuclear deformation, neutron skin, and nucleonic clustering. These collective properties of nuclear structure, leave unique signatures in the initial state of high energy nuclear collisions, therefore offering a straightforward route to establish direct correspondences between the structure of colliding nuclei and the final state observables utilizing the state-of-the-art hydrodynamics. In this seminar, I will review the current experimental measurements, such as anisotropic flow $v_n$, mean transverse momentum $[p_T]$ fluctuations, and their $v_n$-$[p_T]$ correlations from RHIC and the LHC. Significant nuclear quadrupole deformation features are observed in the heavy $^{238}$U nucleus, with the quantitative constraint $\beta_{2, \mathrm{U}} \sim 0.28$. Striking differences are also observed in isobaric collisions of $^{96}$Ru and $^{96}$Zr, where ratios of many bulk observables show substantial departures from unity and exhibit rich patterns as a function of centrality. Comparisons with hydrodynamic simulations suggest a slightly large quadrupole deformation with $\beta_{2, \mathrm{Ru}} \sim 0.16$ of $^{96}$Ru nucleus, a large octupole deformation with $\beta_{3, \mathrm{Zr}} \sim 0.2$ and large neutron skin $a_0$ of $^{96}$Zr nucleus, directly providing the first discovery and quantitative extraction of the nuclear octupole deformation in the intermediate nucleus. In addition, the new measurement of the ratio between two- and four-particle correlations from a large sample of minimum bias and central triggered high energy $^{16}$O collisions in STAR experiment, offers potential topological nucleonic cluster pattern sensitivities for investigating the nuclear force in the light nucleus. Our explorations pave the way for an interdisciplinary connection between low-energy and high-energy connections for deeply understanding the nuclear structure and the initial conditions.

Organized by

Manu Kurian, Raza Sufian