Small shear viscosity in the semiquark gluon plasma

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

DOI:https://doi.org/10.1103/PHYSREVD.81.076002· OSTI ID:21431036

Hidaka, Yoshimasa ^[1]; Pisarski, Robert D ^[2]

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1. Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
2. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)

At nonzero temperature in QCD, about the deconfining phase transition there is a semiquark gluon plasma (semi-QGP), where the expectation value of the (renormalized) Polyakov loop is less than one. This can be modeled by a semiclassical expansion about a constant field for the vector potential, A{sub 0}, which is diagonal in color. We compute the shear viscosity in the semi-QGP by using the Boltzmann equation in the presence of this background field. To leading, logarithmic order in weak coupling, the dominant diagrams are given by the usual scattering processes of 2{yields}2 particles. For simplicity we also assume that both the number of colors and flavors are large. Near the critical temperature T{sub c}, where the expectation value of the Polyakov loop is small, the overall density of colored fields decreases according to their color representation, with the density of quarks vanishes linearly with the loop, and that of gluons, quadratically. This decrease in the overall density dominates changes in the transport cross section. As a result, relative to that in the perturbative QGP, near T{sub c} the shear viscosity in the semi-QGP is suppressed by two powers of the Polyakov loop. In a semiclassical expansion, the suppression of colored fields depends only upon which color representation they lie in, and not upon their mass. That light and heavy quarks are suppressed in a common manner may help to explain the behavior of charm quarks at RHIC.

• OSTI ID: 21431036
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 7; Other Information: DOI: 10.1103/PhysRevD.81.076002; (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
B QUARKS
BOLTZMANN EQUATION
BROOKHAVEN RHIC
C QUARKS
COUPLING
CRITICAL TEMPERATURE
CROSS SECTIONS
DENSITY
EXPANSION
GLUONS
MASS
PARTICLES
PHASE TRANSFORMATIONS
QUANTUM CHROMODYNAMICS
SCATTERING
SEMICLASSICAL APPROXIMATION
T QUARKS
ACCELERATORS
APPROXIMATIONS
BEAUTY PARTICLES
BOSONS
CALCULATION METHODS
CHARM PARTICLES
DIFFERENTIAL EQUATIONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FIELD THEORIES
HEAVY ION ACCELERATORS
INTEGRO-DIFFERENTIAL EQUATIONS
KINETIC EQUATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PHYSICAL PROPERTIES
POSTULATED PARTICLES
QUANTUM FIELD THEORY
QUARKS
STORAGE RINGS
THERMODYNAMIC PROPERTIES
TOP PARTICLES
TRANSITION TEMPERATURE