Quark Matter 2023

Model study on bottomonia modification in small collision systems

5 Sept 2023, 17:30

2h 10m

Grand Ballroom, 4th floor ( Hilton of the Americas)

Poster Heavy Flavor Poster Session

Speaker

Sanghoon Lim (Pusan National University (KR))

Description

Quarkonia have been long considered as key features in heavy ion collision to study the properties of the quark-gluon plasma. One of the key signatures is the sequential yield suppression for different quarkonium states in nucleus-nucleus (A+A) collisions compared to p+p collisions following the ordering of their binding energies. Moreover, sequential yield modification has also been observed in small collision systems such p+Au and p+Pb collisions. Theoretical models consider dissociation and regeneration effects to describe these experimental results, whereas the additional suppression of excited states in small systems is considered to be beyond initial-state effects which is premature to claim for any hot medium effect. To quantitatively test and disentangle such hot medium effects, a model study is performed in various small collision systems such as p+p, p+Pb, p+O, and O+O collisions for $\mathrm{{\rm Y}}(nS)$ production. In this model, we incorporate a theoretical calculation of hot in-medium effects for $\mathrm{{\rm Y}}(nS)$ states into a Monte Carlo simulation to more realistically probe the medium produced in heavy ion collisions with event-by-event initial collision geometry and hydrodynamical evolution. The theory calculation considers gluo-dissociation and inelastic parton scattering for dissociation and their inverse reaction for regeneration and reasonably describes the modification of $\mathrm{{\rm Y}}(1S)$ in Pb+Pb collisions. In this work (Phys. Rev. C 107, 054905 (2023)), we quantify the nuclear modification factor of $\mathrm{{\rm Y}}(nS)$ as a function of charged particle multiplicity ($d{N}_{ch}/d\eta$) and transverse momentum. We also calculate the elliptic flow of $\mathrm{{\rm Y}}(nS)$ in small collision systems. The results are compared with existing experimental results and discussed in terms of prospects for the upcoming LHC oxygen ion run.

Presentation materials

SHINCHON_QM23_v2.pdf