# Initial Stages 2021

Jan 10 – 15, 2021
Weizmann Institute of Science
Asia/Jerusalem timezone
See you at IS2023 in Copenhagen in June 2023

## Probing the partonic degree of freedom in high multiplicity p-Pb at 5.02 TeV collisions.

Jan 10, 2021, 7:45 PM
1h 30m
Patio (vDLCC)

### Patio

#### vDLCC

bullet talk (poster) Partonic structure of protons and nuclei

### Speaker

Wenbin Zhao (Peking University)

### Description

Probing the quark gluon plasma in small system is a hot topic nowadays. By combining the thermal and hard parts, with the Cooper-Frye freeze-out, quark coalescence and hard parton fragmentation hadronization mechanisms, we investigate the $p_T$-spectra, the differential elliptic flow and the number of constituent quark (NCQ) scaling of pions, kaons and protons of high multiplicity p+ Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV. More detailly, at low $p_T$ range, thermal hadrons are generated by the hydrodynamics, at intermediate and high $p_T$ range, we firstly coalescence the thermal and hard quarks, including the thermal-thermal, thermal-hard, hard-hard quark pairs recombinations, then the remnant hard partons those haven't found recombination partners are subjected to string fragmentation. We obtain a satisfactory description of elliptic flow and spectra over the $p_T$ range from 0 to 6 GeV, and demonstrate that the coalescence process is indispensable for the differential elliptic flow and NCQ scaling at intermediate $p_T$. This provides an opportunity to distinguish the origin of the collectivity in high multiplicity p+Pb collisions.
[1] W.Zhao, C.M.Ko, Y.X.Liu, G.Y.Qin and H.Song, Phys.Rev.Lett. 125, 72301 (2020).
[2] W.Zhao, C.M.Ko, Y.X.Liu, G.Y.Qin and H.Song, arXiv:2001.10689 [nucl-th].

### Primary authors

Wenbin Zhao (Peking University) Guang-You Qin (Central China Normal University) Prof. Che-Ming Ko Prof. Yu-Xin Liu (Peking university)

### Presentation materials

 poster_ncq_IS2021_Wenbin_Zhao.pdf slice_wenbin_IS2021.pdf