A stochastic approach to the reconstruction of spectral functions in lattice QCD

Shu H-T, Ding H-T, Kaczmarek O, Mukherjee S, Ohno H. A stochastic approach to the reconstruction of spectral functions in lattice QCD. In: Proceedings, 33rd International Symposium on Lattice Field Theory (Lattice 2015) : Kobe, Japan, July 14-18, 2015. PoS; 2016.We present a Stochastic Optimization Method (SOM) for the reconstruction of the spectral functions (SPFs) from Euclidean correlation functions. In this approach the SPF is parameterized as a sum of randomly distributed boxes. By varying the width, location and height of the boxes stochastically an optimal SPF can be obtained. Using this approach we reproduce mock SPFs fairly well, which contain sharp resonance peaks, transport peaks and continuum spectra. We also analyzed the charmonium correlators obtained from $N_{\tau}$=96, 48, 32 lattices using SOM and found similar conclusion on the dissociation temperatures of charmonium ground states as that obtained using the Maximum Entropy Method