English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Motivated by the observation that there may exist hadronic excitations evenin the quark-gluon plasma (QGP) phase, we investigate how the properties ofquarks, especially within the quasi-particle picture, are affected by thecoupling with bosonic excitations at finite temperature (T), employing  Yukawa models with a massive scalar (pseudoscalar) and vector (axial-vector)boson of mass m. The quark spectral function and the quasi-dispersion relationsare calculated at one-loop order. We find that there appears a three-peakstructure in the quark spectral function with a collective nature when T iscomparable with m, irrespective of the type of boson considered. Such amulti-peak structure was first found in a chiral model yielding scalarcomposite bosons with a decay width. We elucidate the mechanism through whichthe new quark collective excitations are realized in terms of the Landaudamping of a quark (an antiquark) induced by scattering with the thermallyexcited boson, which gives rise to mixing and hence a level repulsion between aquark (antiquark) and an antiquark-hole (quark-hole) in the thermally excitedantiquark (quark) distribution. Our results suggest that the quarks in the QGPphase can be described within an interesting quasi-particle picture with amulti-peak spectral function. Because the models employed here are rathergeneric, our findings may represent a universal phenomenon for fermions coupledto a massive bosonic excitation with a vanishing or small width. The relevanceof these results to other fields of physics, such as neutrino physics, is alsobriefly discussed. In addition, we describe a new aspect of the plasminoexcitation obtained in the hard-thermal loop approximation.Comment: 41 pages, 39 eps figures, version to appear in Prog. Theor. Phys,  comments on effects of the quark mass and the chemical potential added, typos  corrected, some figures improve

Novel Collective Excitations and the Quasi-Particle Picture of Quarks Coupled with a Massive Boson at Finite Temperature