Thermal ensemble of string gas in a magnetic field

TL;DR

This paper investigates the thermodynamics of a free string gas in a magnetic field, revealing a critical magnetic field where the partition function diverges, indicating a possible phase transition and symmetry restoration.

Contribution

It introduces the analysis of a string gas in a magnetic field, identifying a critical field and phase transition behavior not previously explored.

Findings

Partition function diverges above critical magnetic field

First-order phase transition with large latent heat

Infinite states become massless at critical point

Abstract

We study the thermal ensemble of a gas of free strings in presence of a magnetic field. We find that the thermodynamical partition function diverges when the magnetic field exceeds some critical value $B_{\rm cr}$, which depends on the temperature. We argue that there is a first-order phase transition with a large latent heat. At the critical value an infinite number of states -all states in a Regge trajectory- seem to become massless, which may be an indication of recuperation of spontaneously broken symmetries.