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Title: Chiral transition and mesonic excitations for quarks with thermal masses

Abstract

We study the effect of a thermal quark mass, m{sub T}, on the chiral phase transition and mesonic excitations in the light quark sector at finite temperature in a simple chirally symmetric model. We show that, while nonzero m{sub T} lowers the chiral condensate, the chiral transition remains of second order. It is argued that the mesonic excitations have a large decay rate at energies below 2m{sub T}, owing to the Landau damping of the quarks and the van Hove singularities of the collective modes.

Authors:
;  [1]
  1. RIKEN-BNL Research Center, Brookhaven National Laboratory, Building 510A, Upton, New York 11973 (United States)
Publication Date:
OSTI Identifier:
20933194
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevD.75.011901; (c) 2007 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; CHIRAL SYMMETRY; CHIRALITY; D QUARKS; EXCITATION; LANDAU DAMPING; MASS; PARTICLE DECAY; PHASE TRANSFORMATIONS; QUANTUM FIELD THEORY; SINGULARITY; U QUARKS

Citation Formats

Hidaka, Yoshimasa, and Kitazawa, Masakiyo. Chiral transition and mesonic excitations for quarks with thermal masses. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.011901.
Hidaka, Yoshimasa, & Kitazawa, Masakiyo. Chiral transition and mesonic excitations for quarks with thermal masses. United States. doi:10.1103/PHYSREVD.75.011901.
Hidaka, Yoshimasa, and Kitazawa, Masakiyo. Mon . "Chiral transition and mesonic excitations for quarks with thermal masses". United States. doi:10.1103/PHYSREVD.75.011901.
@article{osti_20933194,
title = {Chiral transition and mesonic excitations for quarks with thermal masses},
author = {Hidaka, Yoshimasa and Kitazawa, Masakiyo},
abstractNote = {We study the effect of a thermal quark mass, m{sub T}, on the chiral phase transition and mesonic excitations in the light quark sector at finite temperature in a simple chirally symmetric model. We show that, while nonzero m{sub T} lowers the chiral condensate, the chiral transition remains of second order. It is argued that the mesonic excitations have a large decay rate at energies below 2m{sub T}, owing to the Landau damping of the quarks and the van Hove singularities of the collective modes.},
doi = {10.1103/PHYSREVD.75.011901},
journal = {Physical Review. D, Particles Fields},
number = 1,
volume = 75,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • No abstract prepared.
  • Using constituent quarks coupled to a linear sigma model at nonzero temperature, I show that many anomalous mesonic amplitudes, such as {pi}{sup 0}{r_arrow}{gamma}{gamma}, vanish in a chirally symmetric phase. Processes which are allowed, such as {pi}{sup 0}{sigma}{r_arrow}{gamma}{gamma}, are computed to leading order in a loop expansion. {copyright} {ital 1996 The American Physical Society.}
  • The form factor g{sub {rho}{pi}}{sup (S)}(Q{sup 2}) of the strange vector current transition matrix element {l_angle}{rho}{vert_bar}{bar s}{gamma}{sub {mu}}s{vert_bar}{pi}{r_angle} is calculated within the chiral quark model. A strange vector current of the constituent {ital U} and {ital D} quarks is induced by kaon radiative corrections and this mechanism yields the nonvanishing values of g{sub {rho}{pi}}{sup (S)}(0). The numerical result at the photon point is consistent with the one given by the {phi}-meson dominance model, but the falloff in the Q{sup 2} dependence is faster than the monopole form factor. Mesonic radiative corrections are also examined for the electromagnetic {rho}-to-{pi} and K{supmore » {asterisk}}-to-K transition amplitudes. {copyright} {ital 1998} {ital The American Physical Society}« less
  • Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the quark-level linear {sigma} model, and infrared QCD. This allows to define effective nonstrange and strange current quark masses, which reproduce the experimental pion and kaon masses very accurately, by simple additivity. In contrast, the usual nonstrange and strange current quarks employed by the Particle Data Group and Chiral Perturbation Theory do not allow a straightforward quantitative explanation of the pion and kaon masses.
  • We have simulated lattice QCD directly in the chiral limit of zero quark mass by adding an additional, irrelevant 4-fermion interaction to the standard action. Using lattices having temporal extent of six and spatial extents of twelve and eighteen, we find that the theory with 2 massless staggered quark flavors has a second-order finite-temperature phase transition. The critical exponents {beta}{sub mag}, {delta} and {nu} are measured and favour tricritical behaviour over that expected by universality arguments. The pion screening mass is consistent with zero below the transition, but is degenerate with the nonzero {sigma}(f{sub 0}) mass above the transition, indicatingmore » the restoration of chiral symmetry.« less