The lightest $D_0^\ast$ resonance from lattice QCD

Abstract

We recently presented elastic $I=1/2$ $D\pi$ scattering from lattice QCD at $m_{\pi} = 239$ MeV. The amplitude features a pole corresponding to a mass $m \approx 2200$ MeV and a width $\Gamma \approx 400$ MeV. The results were compared to an earlier study at a higher pion mass and to a similar study in the charm-strange sector. In this contribution to LATTICE2021 I summarize these results and compare them with experiment, based on the values reported by the particle data group. Our result lies significantly below the experimental $D_0^\ast$. I also relate our findings to recent studies in chiral perturbation theory. Based on work presented in JHEP2021(7),123 for the Hadron Spectrum Collaboration.