On the light front surfaces in the phase space of hadrons in heavy-ion collisions

TL;DR

This paper investigates the geometric structure of hadron phase space in heavy-ion collisions, demonstrating that paraboloidal surfaces in phase space can separate particle groups with distinct thermal distributions.

Contribution

It introduces the concept of paraboloidal light front surfaces in phase space and shows their role in dividing particles with different thermal characteristics in simulated collisions.

Findings

Paraboloidal surfaces divide particles into two groups in phase space.

One group exhibits Boltzmann-distributed transverse momentum and angles.

The distributions are characterized by a mass-dependent temperature.

Abstract

Surfaces corresponding to the constant values of the light front variable forms paraboloids in the phase space of the inclusively produced hadrons in heavy-ion collisions. In this paper, it is demonstrated with the simulated Au-Au collisions at $\sqrt{s} = 200$ GeV using the UrQMD event generator that the paraboloidal surface defined by a certain constant value of the light front variable divides the particles in the phase space into two groups such that the distributions of the square of the transverse momentum, the polar angle and the light front variable of particles belonging to one among them can be described with the Boltzmann distribution parameterised by the mass-dependent temperature.