paper

Isospin-1/2 scattering and the lightest resonance from lattice QCD

arXiv:2102.04973 · doi:10.1007/JHEP07(2021)123

Abstract

Isospin-1/2 scattering amplitudes are computed using lattice QCD, working in a single volume of approximately and with a light quark mass corresponding to MeV. The spectrum of the elastic energy region is computed yielding 20 energy levels. Using the Lüscher finite-volume quantisation condition, these energies are translated into constraints on the infinite-volume scattering amplitudes and hence enable us to map out the energy dependence of elastic scattering. By analytically continuing a range of scattering amplitudes, a resonance pole is consistently found strongly coupled to the -wave channel, with a mass MeV and a width MeV. Combined with earlier work investigating the , and with heavier light quarks, similar couplings between each of these scalar states and their relevant meson-meson scattering channels are determined. The mass of the is consistently found well below that of the , in contrast to the currently reported experimental result.

40 pages, 15 figures. Various small changes to match the version accepted by JHEP

References in corpus (13)

Cited by in corpus (27)