Size of the emission source and collectivity in ultra-relativistic p-Pb collisions

TL;DR

This paper investigates the size and collective behavior of the emission source in ultra-relativistic p-Pb collisions using hydrodynamic models, suggesting that central p-Pb collisions exhibit collective expansion similar to peripheral nucleus-nucleus collisions.

Contribution

It introduces a hydrodynamic framework to analyze interferometric radii in p-Pb collisions, highlighting their role as signatures of fireball formation and collective expansion.

Findings

Interferometric radii indicate extended fireball formation.

Central p-Pb collisions show collective expansion akin to peripheral nucleus-nucleus collisions.

Hydrodynamics effectively describes the system's collective behavior.

Abstract

The interferometric radii in the system formed in ultra-relativistic proton-lead collisions are investigated in a framework based on event-by-event 3+1 dimensional viscous hydrodynamics. We argue that the most central p-Pb collisions undergoing collective expansion behave similarly to the peripheral nucleus-nucleus collisions. The interferometric observables can serve as signatures of the formation of an extended fireball.