We determine JPC=0++ and 2++ hadron-hadron scattering amplitudes in the charmonium energy region up to 4100 MeV using lattice QCD, a first-principles approach to QCD. Working at mπ≈391 MeV, more than 200 finite-volume energy levels are computed and these are used in extensions of the L\"uscher formalism to determine infinite-volume coupled-channel scattering amplitudes. We find that this energy region contains a single χc0 and a single χc2 resonance. Both are found as pole singularities on the closest unphysical Riemann sheet, just below 4000 MeV with widths around 70 MeV. The largest couplings are to kinematically-closed D∗Dˉ∗ channels in S-wave, and couplings to several decay channels consisting of pairs of open-charm mesons are found to be large and significant in both cases. Above the ground state χc0, no other scalar bound-states or near-DDˉ threshold resonances are found, in contrast to several theoretical and experimental studies.
@article{arxiv.2309.14070,
title = {Scalar and tensor charmonium resonances in coupled-channel scattering from QCD},
author = {David J. Wilson and Christopher E. Thomas and Jozef J. Dudek and Robert G. Edwards},
journal= {arXiv preprint arXiv:2309.14070},
year = {2024}
}