Reconstruction of smeared spectral functions from Euclidean correlation functions
Gabriela Bailas (Theory Center, High Energy Accelerator Research Organization (KEK), , Tsukuba 305-0801, , Japan); Shoji Hashimoto (Theory Center, High Energy Accelerator Research Organization (KEK), , Tsukuba 305-0801, , Japan); Tsutomu Ishikawa (School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI), , Tsukuba 305-0801, , Japan)
Abstract We propose a method to reconstruct smeared spectral functions from two-point correlation functions measured on the Euclidean lattice. An arbitrary smearing function can be considered as long as it is smooth enough to allow an approximation using Chebyshev polynomials. We test the method with numerical lattice data of charmonium correlators. The method provides a framework to compare lattice calculation with experimental data including excited-state contributions without assuming quark–hadron duality.