Speaker
Description
The lightest scalar charm-light $D_0^\star$ and charm-strange $D_{s0}^\star$ mesons have been puzzling in that experiments have found them at approximately the same mass. This is in contrast with the quark-model prediction. For the first time, we map out the energy dependence of the elastic Isospin-1/2 $D\pi$ scattering amplitude and find a complex $D_0^\star$ resonance pole, using Lattice QCD with a pion mass $m_\pi\approx239$ MeV and the Lüscher finite-volume quantisation condition. The resonance, which is lighter than the $D_{s0}^\star$ found on the same lattice, is strongly coupled to the $S$-wave $D\pi$ channel. We find that both $q\bar{q}$-like and $D\pi$-like constructions are necessary to interpolate the corresponding spectrum from the vacuum.
Based on arXiv:2102.04973
L. Gayer, N. Lang, S. Ryan, D. Tims, C. E. Thomas, D. J. Wilson
for the Hadron Spectrum Collaboration
