Dπ scattering and D meson resonances from lattice QCD

A first exploratory lattice QCD simulation is presented, aimed at extracting the masses and widths of the broad scalar D*(0)(2400) and the axial D-1(2430) charm-light resonances. For that purpose D pi and D*pi scattering are simulated, and the resonance parameters are extracted using a Breit-Wigner fit of the resulting phase shifts. We use a single two-flavor dynamical ensemble with m(pi) approximate to 266 MeV, a similar or equal to 0:124 fm and a rather small volume V = 16(3) X 32. The resulting D*(0)(2400) mass is 351 +/- 21 MeV above the spin average 1/4 (m(D) + 3m(D*)), in agreement with the experimental value of 347 +/- 29 MeV above. The resulting D*(0) -> D pi coupling, g(lat) = 2.55 +/- 0.21 GeV, is close to the experimental value g(exp) <= 1.92 +/- 0.14 GeV, where g parametrizes the width Gamma g(2)p*/s. The resonance parameters for the broad D-1(2430) are also found close to the experimental values; these are obtained by appealing to the heavy quark limit, where the neighboring resonance D-1(2420) is narrow. The calculated I = 1/2 scattering lengths are a(0) = 0.81 +/- 0.14 fm for D pi and a(0) = 0.81 +/- 0.17 fm for D*pi scattering. The simulation of the scattering in these channels incorporates quark-antiquark as well as multihadron interpolators, and the distillation method is used for contractions. In addition, the ground and several excited charm-light and charmonium states with various J(P) are calculated using standard quark-antiquark interpolators. DOI: 10.1103/PhysRevD.87.034501