Equation of state and heavy-quark free energy at finite temperature and density in two flavor lattice QCD with Wilson quark action

Journal Article · Thu Jul 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.014508· OSTI ID:21410053

Ejiri, S ^[1]; Maezawa, Y ^[2]; Ukita, N ^[3]; Aoki, S ^[4]; Hatsuda, T; Ishii, N ^[5]; Kanaya, K ^[4]; Umeda, T ^[6]

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1. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)
2. En'yo Laboratory, RIKEN Nishina Accelerator Research Center, Saitama 351-0198 (Japan)
3. Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)
4. Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan)
5. Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)
6. Graduate School of Education, Hiroshima University, Hiroshima 739-8524 (Japan)

We study the equation of state at finite temperature and density in two-flavor QCD with the renormalization group improved gluon action and the clover-improved Wilson quark action on a 16{sup 3}x4 lattice. Along the lines of constant physics at m{sub PS}/m{sub V}=0.65 and 0.80, we compute the second and forth derivatives of the grand canonical partition function with respect to the quark chemical potential {mu}{sub q}=({mu}{sub u}+{mu}{sub d})/2 and the isospin chemical potential {mu}{sub I}=({mu}{sub u}-{mu}{sub d})/2 at vanishing chemical potentials, and study the behaviors of thermodynamic quantities at finite {mu}{sub q} using these derivatives for the case {mu}{sub I}=0. In particular, we study density fluctuations at nonezero temperature and density by calculating the quark number and isospin susceptibilities and their derivatives with respect to {mu}{sub q}. To suppress statistical fluctuations, we also examine new techniques applicable at low densities. We find a large enhancement in the fluctuation of the quark number when the density increased near the pseudocritical temperature, suggesting a critical point at finite {mu}{sub q} terminating the first order transition line between hadronic and quark-gluon-plasma phases. This result agrees with the previous results using staggered-type quark actions qualitatively. Furthermore, we study heavy-quark free energies and Debye screening masses at finite density by measuring the first and second derivatives of these quantities for various color channels of heavy quark-quark and quark-antiquark pairs. The results suggest that, to the leading order of {mu}{sub q}, the interaction between two quarks becomes stronger at finite densities, while that between quark and antiquark becomes weaker.

• OSTI ID: 21410053
• Journal Information: Physical Review. D, Particles Fields, Vol. 82, Issue 1; Other Information: DOI: 10.1103/PhysRevD.82.014508; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTIQUARKS
B QUARKS
C QUARKS
DENSITY
EQUATIONS OF STATE
FLAVOR MODEL
FLUCTUATIONS
FREE ENERGY
GLUONS
HADRONS
ISOSPIN
MASS
PARTITION FUNCTIONS
QUANTUM CHROMODYNAMICS
QUARK MATTER
QUARK-ANTIQUARK INTERACTIONS
RENORMALIZATION
T QUARKS
ANTIMATTER
ANTIPARTICLES
BEAUTY PARTICLES
BOSONS
CHARM PARTICLES
COMPOSITE MODELS
ELEMENTARY PARTICLES
ENERGY
EQUATIONS
FERMIONS
FIELD THEORIES
FUNCTIONS
INTERACTIONS
MATHEMATICAL MODELS
MATTER
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
POSTULATED PARTICLES
QUANTUM FIELD THEORY
QUARK MODEL
QUARKS
THERMODYNAMIC PROPERTIES
TOP PARTICLES
VARIATIONS