Pion, kaon, and proton femtoscopy in Pb--Pb collisions at $\sqrt{s_{\rm NN}}$=2.76 TeV modeled in 3+1D hydrodynamics

TL;DR

This paper uses 3+1D hydrodynamics to model femtoscopic measurements of pions, kaons, and protons in Pb--Pb collisions at 2.76 TeV, revealing universal scaling behaviors related to system size and collective flow.

Contribution

It introduces a comprehensive 3+1D hydrodynamic model coupled with statistical hadronization to analyze femtoscopic radii for multiple particle species at LHC energies.

Findings

Femtoscopic radii depend on pair transverse momentum and collision centrality.

Universal scaling of radii with pair transverse mass and multiplicity observed.

Results support the interpretation of strong collective flow in heavy-ion collisions.

Abstract

Femtoscopy is providing information on system size and its dynamics in heavy-ion collisions. At ultra-relativistic energies, such as those obtained at the LHC, significant production of pions, kaons and protons enables femtoscopic measurements for these particles. In particular the dependence of system size on pair momentum and particle type is interpreted as evidence for strong collective flow. Such phenomena are naturally modeled by hydrodynamics. We present calculations within the 3+1D hydrodynamic model coupled to statistical hadronization code THERMINATOR 2, corresponding to Pb--Pb collisions at $\sqrt{s_{\rm NN}}=$2.76 TeV. We obtain femtoscopic radii for pions, kaons, and protons, as a function of pair transverse momentum and collision centrality. We find that an approximate universal scaling of radii with pair transverse mass and final state event multiplicity is observed, and discuss the consequences for the interpretation of experimental measurements.