Spectral reconstruction of Euclidean correlator moments in lattice QCD

Abstract

A novel application of lattice QCD spectral reconstruction is presented, in which euclidean correlation function data in a fixed time range are used to infer values outside the range, enabling a model-independent investigation of the asymptotic large-time behavior. Moments of the correlator are also determined, and reconstructed correlation matrices between different moments are included in a variational optimization similar to the standard Generalized Eigenvalue Problem (GEVP). These ideas are illustrated using a single-nucleon correlation function determined on an $N_{\rm}=2+1$ ensemble of gauge configurations at $m_{\pi} = 200{\rm MeV}$.