# Anisotropic hydrodynamic modeling of 2.76 TeV Pb-Pb collisions

## TL;DR

This paper demonstrates that 3+1d quasiparticle anisotropic hydrodynamics accurately models various observables in 2.76 TeV Pb-Pb collisions at the LHC, matching experimental data well.

## Contribution

It introduces a quasiparticle anisotropic hydrodynamics model with temperature-dependent mass fitted to lattice QCD, improving the description of heavy-ion collision dynamics.

## Key findings

- Good agreement with experimental particle spectra.
- Accurate reproduction of elliptic flow and HBT radii.
- Model captures shear and bulk viscosity effects.

## Abstract

We compare phenomenological results from 3+1d quasiparticle anisotropic hydrodynamics (aHydroQP) with experimental data collected in LHC 2.76 TeV Pb-Pb collisions. In particular, we present comparisons of particle spectra, average transverse momentum, elliptic flow, and HBT radii. The aHydroQP model relies on the introduction of a single temperature-dependent quasiparticle mass which is fit to lattice QCD data. By taking moments of the resulting Boltzmann equation, we obtain the dynamical equations used in the hydrodynamic stage which include the effects of both shear and bulk viscosities. At freeze-out, we use anisotropic Cooper-Frye freeze-out performed on a fixed-energy-density hypersurface to convert to hadrons. To model the production and decays of the hadrons we use THERMINATOR 2 which is customized to sample from ellipsoidal momentum-space distribution functions. Using smooth Glauber initial conditions, we find very good agreement with many heavy-ion collision observables.