Neutron star mass limit at 2M_{☉} supports the existence of a CEP
Abstract
We point out that the very existence of a "horizontal branch" in the massradius characteristics for neutron stars indicates a strong firstorder phase transition and thus supports the existence of a critical endpoint (CEP) of firstorder phase transitions in the QCD phase diagram. This branch would sample a sequence of hybrid stars with quark matter core, leading to the endpoint of stable compact star configurations with the highest possible baryon densities. Since we know of the existence of compact stars with 2 M_{☉}, this hypothetical branch has to lie in the vicinity of this mass value, if it exists. We report here a correlation between the maximal radius of the horizontal branch and the pressure at the onset of hadrontoquark matter phase transition, which is likely to be a universal quantity of utmost relevance to the upcoming experiments with heavyion collisions at NICA and FAIR.
 Publication:

European Physical Journal A
 Pub Date:
 August 2016
 DOI:
 10.1140/epja/i2016162329
 arXiv:
 arXiv:1608.02425
 Bibcode:
 2016EPJA...52..232A
 Keywords:

 Nuclear Theory;
 Astrophysics  High Energy Astrophysical Phenomena;
 High Energy Physics  Phenomenology
 EPrint:
 9 pages, 3 figures, accepted for publication in Eur. Phys. J. A