# Correlation femtoscopy study at NICA and STAR energies within a viscous hydrodynamic plus cascade model

## TL;DR

This paper investigates particle emission characteristics in heavy-ion collisions at various energies using a viscous hydrodynamic plus cascade model, linking femtoscopy measurements to the equation of state of hot QCD matter.

## Contribution

It introduces femtoscopic observable calculations within a viscous hydro + cascade model across a range of collision energies, exploring the impact of different equations of state.

## Key findings

- Femtoscopic observables vary with collision energy and EoS.
- The model reproduces key features of experimental femtoscopy data.
- Insights into the QCD phase diagram from energy-dependent femtoscopic measurements.

## Abstract

Correlation femtoscopy allows one to measure the space-time characteristics of particle production in relativistic heavy-ion collisions due to the effects of quantum statistics (QS) and final state interactions (FSI). The main features of the femtoscopy measurements at top RHIC and LHC energies are considered as a manifestation of strong collective flow and are well interpreted within hydrodynamic models employing equation of state (EoS) with a crossover type transition between Quark-Gluon Plasma (QGP) and hadron gas phases. The femtoscopy at lower energies was intensively studied at AGS and SPS accelerators and is being studied now in the Beam Energy Scan program (BES) at the BNL Relativistic Heavy Ion Collider in the context of exploration of the QCD phase diagram. In this article we present femtoscopic observables calculated for Au-Au collisions at $\sqrt{s_{NN}} = 7.7 - 62.4$ GeV in a viscous hydro + cascade model vHLLE+UrQMD and their dependence on the EoS of thermalized matter.