Speaker
Description
In this talk, I will discuss spectral reconstruction from various lattice correlators, with a primary focus on spectral reconstruction related to photon production rates.
Thermal photons are a vital tool for studying the Quark-Gluon Plasma (QGP). The photon production rate from the plasma at temperature is proportional to the transverse spectral function $\rho_T(\omega,\vec k)$. The photon production rate can be calculated from the difference between the transverse $\rho_T(\omega,\vec k)$ and longitudinal $\rho_L(\omega,\vec k)$ correlators, as $\rho_L$ vanishes at the light cone. The UV part of $\rho_T(\omega,\vec k)-\rho_L(\omega,\vec k)$ is suppressed, resulting in the Euclidean correlator primarily capturing contributions from the IR part of $\rho_T(\omega,\vec k)-\rho_L(\omega,\vec k)$. To explore these concepts, we calculate the T-L correlator on $N_f=2+1$ flavor Highly Improved Staggered Quark (HISQ) configurations, as well as on quenched QCD. We showcase various methods of spectral reconstruction from these correlators and compare the estimated photon production rates obtained.
Additionally, I will discuss other ongoing research that requires spectral reconstruction. I will touch upon topics such as the thermal static quark-antiquark potential, pseudo scalar spectral function for quarkonium, and heavy quark diffusion coefficients.
