Finite-volume effects and meson scattering in the 2-flavour Schwinger model (2112.15228v1)

Abstract: We investigate the 2-flavour Schwinger model in the canonical formulation with fixed fermion numbers. We use Wilson fermions and a formalism which describes the determinant of the Dirac operator in terms of dimensionally reduced canonical transfer matrices. These transfer matrices allow the direct examination of arbitrary multi-particle (meson) sectors and the determination of the corresponding ground-state energies. We discuss the finite-volume effects in the meson mass. From the 2-meson energies, we determine the scattering phase shifts and compare the 3-meson energies at finite volume to predictions based on 3-particle quantization conditions.