Thermal spectrum of pseudo-scalar glueballs and Debye screening mass from holography

Nelson R. F. Braga,Luiz F. Ferreira

doi:10.1140/epjc/s10052-017-5232-8

Nelson R. F. Braga, Luiz F. Ferreira

Open Access

https://doi.org/10.1140/epjc/s10052-017-5232-8

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Abstract

The finite temperature spectrum of pseudo-scalar glueballs in a plasma is studied using a holographic model. The 0^{-+} glueball is represented by a pseudo-scalar (axion) field living in a five dimensional geometry that comes from a solution of Einstein equations for gravity coupled with a dilaton scalar field. The spectral function obtained from the model shows a clear peak corresponding to the quasi-particle ground state. Analyzing the variation of the position of the peak with temperature, we describe the thermal behavior of the Debye screening mass of the plasma. As a check of consistency, the zero temperature limit of the model is also investigated. The glueball masses obtained are consistent with previous lattice results.

Highlights

The anti-de Sitter (AdS)/CFT correspondence [1,2,3,4] inspired the development of holographic models that describe strong interaction properties based on gauge/string duality
Some of the first work in this direction assumed the existence of an approximate duality between a field theory living in some ad hoc deformation of anti-de Sitter (AdS) space containing a dimension-full parameter and a gauge theory where the parameter plays the role of an energy scale
The simplest example is the hard wall AdS/QCD model, which appeared in Refs. [5,6,7]

Summary

Introduction

The AdS/CFT correspondence [1,2,3,4] inspired the development of holographic models that describe strong interaction properties based on gauge/string duality. It consists in placing a hard geometrical cutoff in AdS space This model provides, in a very simple way, glueballs masses consistent with lattice results. Another AdS/QCD model, the soft wall, where the square of the mass grow linearly with the radial excitation number, was introduced in Ref. The corresponding finite temperature versions of AdS/QCD models provide a nice picture of the confinement/deconfinement thermal phase transition [11,12,13]. The approach that we will follow is to study the thermal spectrum of pseudo-scalar 0−+ glueballs. These particles are dual to the axion field in gauge gravity duality.

Holographic model with thermal phase transition

Debye screening mass

Spectral function for pseudo-scalar glueballs

Results

Analysis of the results