Volume fluctuations affect on transport and thermodynamic coefficients in p-Pb systems

TL;DR

This study investigates how volume fluctuations in p-Pb collisions influence transport and thermodynamic properties, revealing significant dependence on space-time volume variations using the AMPT model.

Contribution

It introduces two definitions of radius to analyze volume fluctuations and demonstrates their impact on transport and thermodynamic coefficients in small collision systems.

Findings

Transport coefficients vary significantly with volume definitions.

Medium properties depend on space-time volume fluctuations.

Results highlight the importance of volume fluctuations in small systems.

Abstract

We use A Multi-Phase Transport (AMPT) model to simulate the event-by-event p-Pb collisions at $\sqrt{s_{NN}}$=5.02 TeV. To study the space-time volume fluctuations, two different definitions of radius have been introduced in the calculation: One is weigh of event-by-event charged multiplicity (noted as set I), and the other one is weigh of energy density in a single event (notes as set II). Based on calculations of sets I and II, the transport and thermodynamic coefficients, such as the speed of sound squared, shear viscosity, bulk viscosity, and mean free path are both dependent on the radius and local temperature. By comparing results of sets I and II, we found that these transport and thermodynamic coefficients differed significantly in the results. These results imply that the transport and thermodynamic properties of the medium in small collisions significantly depend on the space-time volume fluctuations.