Sensitivity of the Polyakov loop and related observables to chiral symmetry restoration
Abstract
While the Polyakov loop is an order parameter of the deconfinement transition in the heavy quark mass regime of QCD, its sensitivity to the deconfinement of light, dynamical quarks in QCD are not apparent. On the other hand, the quark mass dependence of the Polyakov loop is sensitive to the appearance of a chiral phase transition. Using lattice QCD calculations in the staggered fermion discretization scheme at finite values of the lattice spacing, a T =1 /8 , we show here, for the first time, that the Polyakov loop expectation value, and the heavy quark free energy extracted from it, behaves like an energylike observable in the vicinity of the chiral phase transition temperature T_{c}. Consistent with scaling behavior of energylike observables in the 3 d , O(2 ) universality class, the quark mass derivatives diverge in the chiral limit at T_{c} while the temperature derivatives stay finite. The latter will develop a characteristic spike at T_{c}. This, however, may be resolved only in calculations with quark masses being 2 orders of magnitude smaller than those currently accessible in lattice QCD calculations.
 Publication:

Physical Review D
 Pub Date:
 January 2021
 DOI:
 10.1103/PhysRevD.103.L011501
 arXiv:
 arXiv:2008.11678
 Bibcode:
 2021PhRvD.103L1501C
 Keywords:

 High Energy Physics  Lattice;
 High Energy Physics  Phenomenology;
 Nuclear Theory
 EPrint:
 6 pages, 3 figures