Eur. Phys. J. A (2016) 52: 262
https://doi.org/10.1140/epja/i2016-16262-3

Regular Article - Theoretical Physics

Imprints of a critical point on photon emission

¹ Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstr. 400, D-01328, Dresden, Germany
² Institut für Theoretische Physik, Technische Universität Dresden, D-01062, Dresden, Germany

^* e-mail: f.wunderlich@hzdr.de

Received: 17 September 2015
Accepted: 13 November 2015
Published online: 24 August 2016

Abstract

The linear sigma model with linearized fluctuations of all involved fields facilitates the onset of a sequence of first-order phase transitions at a critical point. This phase structure has distinctive imprints on the photon emission rates. We argue that analogously a critical point in the QCD phase diagram manifests itself by peculiarities of the photon spectra, in particular when the dynamical expansion path of matter crosses the phase transition curve in the vicinity of the critical point.