Kinetic freeze out from an anisotropic fluid in high-energy heavy-ion collisions: particle spectra, Hanbury Brown-Twiss radii, and anisotropic flow

Abstract

Dissipative relativistic fluid-dynamical descriptions of the extended fireball formed in high-energy heavy-ion collisions are quite successful, yet require a prescription for converting the fluid into particles. We present arguments in favour of using a locally anisotropic momentum distribution for the particles emitted from the fluid, so as to smooth out discontinuities introduced by the usual conversion prescriptions. Building on this ansatz, we investigate the effect of the asymmetry on several observables of heavy ion physics.