Maximum entropy analysis of hadron spectral functions and excited states in quenched lattice QCD

TL;DR

This paper uses the maximum entropy method to extract spectral functions from meson correlators in quenched lattice QCD, confirming known results and providing new estimates for excited states.

Contribution

It applies the maximum entropy method to analyze hadron spectral functions and excited states in quenched lattice QCD, offering a novel approach and results.

Findings

Spectral functions extracted consistent with exponential fits

First excited state masses estimated: $m_{\pi_1} = 660(590)$ MeV, $m_{\rho_1} = 1540(570)$ MeV

Decay constant for the first excited rho state obtained: $f_{\rho_1} = 0.085(36)$

Abstract

Employing the maximum entropy method we extract the spectral functions from meson correlators at four lattice spacings in quenched QCD with the Wilson quark action. We confirm that the masses and decay constants, obtained from the position and the area of peaks, agree well with the results from the conventional exponential fit. For the first excited state, we obtain $m_{\pi_1} = 660(590)$ MeV, $m_{\rho_1} = 1540(570)$ MeV, and $f_{\rho_1} = 0.085(36)$ in the continuum limit.