Black-hole quasinormal modes and scalar glueballs in a finite-temperature AdS/QCD model

TL;DR

This paper investigates scalar glueball spectra at finite temperature using a holographic AdS/QCD model, analyzing quasinormal modes and spectral functions to understand thermal effects on glueball properties.

Contribution

It introduces a finite-temperature AdS/QCD soft-wall model to compute scalar glueball spectra and quasinormal modes, providing new insights into thermal behavior in holographic QCD.

Findings

Quasiparticle peaks appear at low temperatures in the spectral function.

Quasinormal modes depend on temperature and momentum.

Peak positions and widths relate to quasinormal mode frequencies.

Abstract

We use the holographic AdS/QCD soft-wall model to investigate the spectrum of scalar glueballs in a finite temperature plasma. In this model, glueballs are described by a massless scalar field in an AdS_5 black hole with a dilaton soft-wall background. Using AdS/CFT prescriptions, we compute the boundary retarded Green's function. The corresponding thermal spectral function shows quasiparticle peaks at low temperatures. We also compute the quasinormal modes of the scalar field in the soft-wall black hole geometry. The temperature and momentum dependences of these modes are analyzed. The positions and widths of the peaks of the spectral function are related to the frequencies of the quasinormal modes. Our numerical results are found employing the power series method and the computation of Breit-Wigner resonances.