Holographic model for charmonium dissociation

Nelson R.F Braga,Luiz F Ferreira,Alfredo Vega

doi:10.1016/j.physletb.2017.10.013

Nelson R.F Braga, Luiz F Ferreira + Show 1 more

Open Access

https://doi.org/10.1016/j.physletb.2017.10.013

Copy DOI

Abstract

We present a holographic bottom up model for the thermal behavior of cc¯ vector mesons in a finite temperature and density plasma. There is a clear physical interpretation for the three input energy parameters of the model. Two of them are related to the mass spectrum of the heavy meson. Namely the quark mass and the string tension of the quark–anti-quark interaction. The third parameter is a large energy scale associated with the non-hadronic meson decay. In such a process the heavy meson is transformed into a much lighter state by electroweak processes. The corresponding transition amplitude is assumed to depend on the energy scale associated with this large mass variation. With this three parameter model one can fit the masses and decay constants of J/Ψ and three radial excitations with an rms error of 20.7%. Using the geometry of a charged black hole, one finds the spectral function for charmonium states inside a plasma at finite temperature and density. The charmonium dissociation in the medium is represented by the decrease in the height of the spectral function peaks.

Highlights

Heavy vector mesons, detected after a heavy ion collision, can provide information about the possible existence of a plasma state for very short time scales
Experimental data show that decay constants decrease monotonically with radial excitation level
It was shown in ref. [5] that the addition of an ultraviolet (UV) energy parameter in the soft wall model, associated with the non hadronic decay of mesons, leads to decay constants decreasing with excitation level, The model includes two energy parameters: the infrared mass scale of the soft wall and the UV scale that is the inverse of the position of anti-de Sitter space where correlation functions are calculated

Summary

INTRODUCTION

Heavy vector mesons, detected after a heavy ion collision, can provide information about the possible existence of a plasma state for very short time scales. Experimental data show that decay constants decrease monotonically with radial excitation level This fact was contrasting with results of previous holographic models. The quasi-particle states appear in the spectral function as smeared peaks that decrease as the temperature T and/or the density μ of the medium increase. This analysis suggests that a consistent extension of a hadronic model to finite temperature should take into account the zero temperature behavior, where decay constants play an essential role. The purpose of this letter is to develop a holographic model for charmonium with three parameters, with the roles discussed above: quark mass, string tension and mass transition scale for non hadronic decay.

HOLOGRAPHIC MODEL FOR CHARMONIUM MASSES AND DECAY CONSTANTS

FINITE DENSITY PLASMA

SPECTRAL FUNCTION

RESULTS AND DISCUSSION