Using a new analysis method to extract excited states in the scalar meson sector

Abstract

We explore a method to extract energy eigenstates, called Athens Model Independent Analysis Scheme (AMIAS), which is an alternative to solving standard Generalized Eigenvalue Problems (GEVP). The method is based on statistically sampling the space of fit parameters according to the χ2 value of the fit function. The method is particularly suited for correlators or correlation matrices with strong contributions from several energy eigenstates and for rather noisy data, e.g. for correlators with disconnected and partly disconnected diagrams. We apply the method to the analysis of the JP =0+ channel in the context of our investigation of the a0(980) meson and point out advantages compared to the GEVP. © Copyright owned by the author(s).