Magnetic equation of state in (2+1)-flavor QCD
- Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)
- Fakultaet fuer Physik, Universitaet Bielefeld, D-33615 Bielefeld (Germany)
- ExtreMe Matter Institute (EMMI), GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, D-64291 Darmstadt (Germany)
A first study of critical behavior in the vicinity of the chiral phase transition of (2+1)-flavor QCD is presented. We analyze the quark mass and volume dependence of the chiral condensate and chiral susceptibilities in QCD with two degenerate light quark masses and a strange quark. The strange quark mass (m{sub s}) is chosen close to its physical value; the two degenerate light quark masses (m{sub l}) are varied in a wide range 1/80{<=}m{sub l}/m{sub s}{<=}2/5, where the smallest light quark mass value corresponds to a pseudoscalar Goldstone mass of about 75 MeV. All calculations are performed with staggered fermions on lattices with temporal extent N{sub {tau}}=4. We show that numerical results are consistent with O(N) scaling in the chiral limit. We find that in the region of physical light quark mass values, m{sub l}/m{sub s}{approx_equal}1/20, the temperature and quark mass dependence of the chiral condensate is already dominated by universal properties of QCD that are encoded in the scaling function for the chiral order parameter, the magnetic equation of state. We also provide evidence for the influence of thermal fluctuations of Goldstone modes on the chiral condensate at finite temperature. At temperatures below, but close to the chiral phase transition at vanishing quark mass, this leads to a characteristic dependence of the light quark chiral condensate on the square root of the light quark mass.
- OSTI ID:
- 21325485
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 80, Issue 9; Other Information: DOI: 10.1103/PhysRevD.80.094505; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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