Isospin-1/2 Dπ scattering and the lightest D0* resonance from lattice QCD

Isospin-1/2 D pi scattering amplitudes are computed using lattice QCD, working in a single volume of approximately (3.6 fm)(3) and with a light quark mass corresponding to m(pi) approximate to 239 MeV. The spectrum of the elastic D pi energy region is computed yielding 20 energy levels. Using the Luscher 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 D pi scattering. By analytically continuing a range of scattering amplitudes, a D-0* resonance pole is consistently found strongly coupled to the S-wave D pi channel, with a mass m approximate to 2200 MeV and a width Gamma approximate to 400 MeV. Combined with earlier work investigating the D-s0*, and D-0* 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 D-0* is consistently found well below that of the D-s0*, in contrast to the currently reported experimental result.

Automated summary

The scattering amplitudes of isospin-1/2 D pi are computed using lattice QCD, revealing a D-0* resonance pole strongly coupled to the S-wave D pi channel. This resonant state has a mass of approximately 2200 MeV and a width of around 400 MeV, consistently found below the mass of the D-s0*.