A systematic study of the initial state in heavy ion collisions based on the quark participant assumption

TL;DR

This paper examines the initial geometric state in heavy ion collisions using a quark participant model, comparing it to the nucleon model, and finds it better explains multiplicity and spatial eccentricity data, especially in small systems.

Contribution

It introduces a systematic comparison of quark versus nucleon participant assumptions in modeling initial states of heavy ion collisions.

Findings

Quark participant assumption improves data description in multiplicity production.

Quark model better captures initial spatial eccentricity in small systems.

Comparison shows significance of quark-level modeling in collision initial states.

Abstract

We investigate the initial state geometric quantities of heavy ion collisions based on the quark participant assumption in the Glauber multiple scattering approach. A systematic comparison to the nucleon participant assumption has been presented and confronted with the charged multiplicity measurements in various collision systems. It is found that the quark participant based assumption can be important to understand the data in multiplicity production and the initial spatial eccentricity in small systems.