NRQCD Bottomonium at non-zero temperature using time-derivative moments

TL;DR

This paper introduces a method using time-derivative moments to extract bottomonium spectral properties at finite temperature from lattice QCD data, providing results consistent with experiments at zero temperature and comparable to other methods at higher temperatures.

Contribution

The paper presents a novel approach using time-derivative moments to determine bottomonium spectral functions and thermal widths at non-zero temperature.

Findings

Zero temperature results match experimental data.

Thermal mass and width vary with temperature.

Method yields results similar to existing approaches at high temperatures.

Abstract

A well-known challenge for the lattice community is calculating the spectral function from the Euclidean correlator. We have approximated the spectral function and derived the mass and thermal width of particles through the time derivatives of the lattice correlator moments. We have focused on extracting the properties of bottomonium states, specifically $\Upsilon$ and $\chi_{b1}$. We will give an overview of the time-derivative moments approach and present results for the temperature dependence of the mass and width of both bottomonium states. The zero temperature results are consistent with experimental values, while results at higher temperatures are similar to those obtained using other methods.