Dissipative effects on quarkonium spectral functions

TL;DR

This paper investigates how dissipative effects influence quarkonium spectral functions at finite temperature, highlighting the importance of including dissipation in potential-based models for accurate descriptions.

Contribution

It introduces a path integral approach incorporating dissipation via a drag coefficient and demonstrates the significant impact of dissipation on quarkonium spectral functions.

Findings

Significant modifications to the 1S quarkonium spectral function due to dissipation.

Path-integral Monte Carlo achieves high-accuracy Euclidean Green functions.

Challenges in spectral function deconvolution are discussed in detail.

Abstract

Quarkonium at finite temperature is described as an open quantum system whose dynamics are determined by a potential $V_R({\bf x})$ and drag coefficient $\eta$, using a path integral with a non-local term. Path-integral Monte Carlo calculations determine the Euclidean Green function for this system to an accuracy greater than one part in a thousand and the maximum entropy method is used to determine the spectral function; challenges facing any kind of deconvolution are discussed in detail with the aim of developing intuition for when deconvolution is possible. Significant changes to the quarkonium spectral function in the $1S$ channel are found, suggesting that any description of quarkonium at finite temperature, using a potential, must also carefully consider the effect of dissipation.