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Title: Structure functions and pair correlations of the quark-gluon plasma

Abstract

Recent experiments at RHIC and theoretical considerations indicate that the quark-gluon plasma, present in the fireball of relativistic heavy-ion collisions, might be in a liquid phase. The liquid state can be identified by characteristic correlation and structure functions. Here definitions of the structure functions and pair correlations of the quark-gluon plasma are presented as well as perturbative results. These definitions might be useful for verifying the quark-gluon-plasma liquid in QCD lattice calculations.

Authors:
 [1]
  1. Max-Planck-Institut fuer extraterrestrische Physik, P.O. Box 1312, 85741 Garching (Germany)
Publication Date:
OSTI Identifier:
20713844
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 72; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.72.094030; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BROOKHAVEN RHIC; CORRELATIONS; FIREBALL MODEL; HEAVY ION REACTIONS; LATTICE FIELD THEORY; PERTURBATION THEORY; QUANTUM CHROMODYNAMICS; QUARK MATTER; RELATIVISTIC RANGE; STRUCTURE FUNCTIONS

Citation Formats

Thoma, Markus H. Structure functions and pair correlations of the quark-gluon plasma. United States: N. p., 2005. Web. doi:10.1103/PhysRevD.72.094030.
Thoma, Markus H. Structure functions and pair correlations of the quark-gluon plasma. United States. doi:10.1103/PhysRevD.72.094030.
Thoma, Markus H. Tue . "Structure functions and pair correlations of the quark-gluon plasma". United States. doi:10.1103/PhysRevD.72.094030.
@article{osti_20713844,
title = {Structure functions and pair correlations of the quark-gluon plasma},
author = {Thoma, Markus H.},
abstractNote = {Recent experiments at RHIC and theoretical considerations indicate that the quark-gluon plasma, present in the fireball of relativistic heavy-ion collisions, might be in a liquid phase. The liquid state can be identified by characteristic correlation and structure functions. Here definitions of the structure functions and pair correlations of the quark-gluon plasma are presented as well as perturbative results. These definitions might be useful for verifying the quark-gluon-plasma liquid in QCD lattice calculations.},
doi = {10.1103/PhysRevD.72.094030},
journal = {Physical Review. D, Particles Fields},
number = 9,
volume = 72,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}
  • Starting from a classical kinetic description of the quark-gluon plasma, we derive in the linear response approximation the color response function near thermodynamic equilibrium. From its poles the dispersion relations for the collective color modes (one longitudinal and one transverse) are obtained. The absence of Landau damping in the quark-gluon plasma is shown, and other damping mechanisms are discussed. A common misunderstanding concerning Landau damping in an electron plasma at low momenta is clarified. Finally we find the color correlation function in an equilibrium QCD plasma, using the fluctuation-dissipation theorem. Its relation to the gluon polarization operator in finite temperaturemore » QCD is discussed. The coefficient for color transport (color conductivity) is determined within a relaxation time model. Possible applications in the computation of plasma observables are pointed out.« less
  • We investigate dynamical plasma screening effects on a heavy-quark--antiquark pair traversing a quark-gluon plasma. The screened potential created by a test charge (heavy quark) moving in the plasma medium is calculated in the test charge frame by solving the transport equation for a collisionless ultrarelativistic plasma interacting via Abelian gauge field. It is shown that the screened potential becomes strongly anisotropic as the velocity of the plasma medium increases. Possible implications of this effect for charmonium production in relativistic heavy-ion collisions are discussed.
  • We investigate the consequences of space-momentum correlations in quark phase-space distributions for coalescence processes at the hadronization transition. Thus far it has been proved difficult to reconcile such correlations with the empirically observed constituent quark number scaling (CQNS) at the Relativistic Heavy Ion Collider (RHIC). To address this problem we combine our earlier developed quark recombination model with quark phase-space distributions computed from relativistic Langevin simulations in an expanding quark-gluon plasma (QGP). Hadronization is based on resonance formation within a Boltzmann equation that recovers thermal equilibrium and obeys energy conservation in the quark-coalescence process, while the fireball background is adjustedmore » to hydrodynamic simulations of semicentral Au-Au collisions at RHIC. To facilitate the applicability of the Langevin process, we focus on strange and charm quarks. Their interactions in the QGP are modeled using leading-order perturbative QCD augmented by effective Lagrangians with resonances that smoothly merge into hadronic states formed at T{sub c}. The interaction strength is adjusted to reproduce the empirical saturation value for the quark-elliptic flow, v{sub 2,q}{sup sat}{approx_equal}7-8%. The resulting {phi} and J/{psi} elliptic flow recover CQNS over a large range in transverse momentum (p{sub T}) within a few percent. As a function of transverse kinetic energy, both the quark spectra from the Langevin simulations and the meson spectra generated via resonance recombination recover CQNS from zero to at least 3 GeV.« less
  • Lepton-pair production from a quark-gluon plasma is calculated to first order in [alpha][sub [ital s]]. The full kinematic region is considered, i.e., also when the lepton pair is moving. The crossing symmetry at finite temperature is discussed for positive as well as negative values of [ital q][sup 2], the invariant mass of the lepton pair. The cancellation of collinear singularities and infrared divergences between the different contributions is explicitly shown. The final result is presented in the form of a well-defined double integral over energies of constituents.
  • A lepton-pair production mechanism induced by the interaction of quarks with the collective color field confining them is discussed. The intensity of pair production is estimated and the invariant-mass spectrum is calculated.