Spectral properties of massless and massive quarks coupled with massive boson at finite temperature

Abstract

We study the properties of massless and massive quarks coupled with a scalar and pseudoscalar boson at finite temperature in Yukawa models at the one-loop order. The behavior of the spectral function and the pole structure of the propagator are analyzed as functions of temperature $T$ and the quark mass $m_f$. It is shown that the three-peak structure of the spectral function found in a previous work for massless quarks is formed at temperatures comparable to the boson mass even for finite $m_f$, but gradually ceases to exist as $m_f$ becomes larger. We identify the three poles of the quark propagator corresponding to the collective excitations of the quark in the complex energy plane. It is shown that the three trajectories made by the poles along with a variation of $T$ undergo a structural rearrangement at a critical quark mass when $m_f$ is increased. This suggests that the physics content of the collective quark excitations is changed in a drastic way at this point. The results are nicely accounted for with the notion of the level mixing induced by a resonant scattering of the massive boson with quarks and holes of thermally excited anti-quarks.

16 pages, 36 eps figures. Accepted for publication in Physical Reviw D

References in corpus (6)

• Quarkonium correlators and spectral functions at zero and finite temperature
• Charmonium at high temperature in two-flavor QCD
• Charmonium properties in deconfinement phase in anisotropic lattice QCD
• Novel Collective Excitations and the Quasi-Particle Picture of Quarks Coupled with a Massive Boson at Finite Temperature
• Spectral properties of quarks above T_c in quenched lattice QCD
• Quasi-quark spectrum in the chiral symmetric phase from the Schwinger-Dyson equation

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• Structure of a thermal quasifermion in the QCD/QED Medium
• Recent progress in hard-thermal-loop QCD thermodynamics and collective excitations
• Emergence of soft quark excitations by the coupling with a soft mode of the QCD critical point
• Diagrammatic and Kinetic Equation Analysis of Ultrasoft Fermionic Sector in Quark-Gluon Plasma
• Spectral properties of quarks above Tc -- thermal mass, dispersion relation, and self-energy --