Dynamics of Quark Gluon Plasma and Interference of Thermal Photons

TL;DR

This paper explores how intensity interferometry of thermal photons in heavy ion collisions can reveal the space-time evolution, phase transition temperature, and equation of state of quark-gluon plasma.

Contribution

It demonstrates the sensitivity of photon correlation functions to the phase transition temperature and the equation of state, providing a novel probe for quark-gluon plasma properties.

Findings

Correlation functions distinguish between different equations of state.

Photon interference reveals system lifetime and phase transition details.

Results are sensitive to the quark-hadron phase transition temperature.

Abstract

The quantum statistical interference between identical particles emitted from a completely chaotic source is expected to provide valuable input for the space time description of the system. Intensity interferometry of thermal photons produced in heavy ion collisions is a very promising tool to explore the structure and dynamics of the collision fireball. Thermal photons having $K_T \, \le \, 2$ GeV/$c$ get competing contribution from both hadronic and quark matter phases and this competition gives rise to a rich structure in the outward correlation function, owing to the interference between the photons from the two sources. The temporal separation between the two sources provides the lifetime of the system and the correlation results are found to be sensitive to quark hadron phase transition temperature and the formation time of the plasma. The outward correlation function strongly depends on the equation of state of the strongly interacting matter and is seen to clearly distinguish between the lattice based and bag model equations of state.