Scattering amplitudes with scalar and tensor charmonium resonances are computed using lattice QCD. Working at $m_\pi\approx 391$ MeV, more than 200 finitevolume energy levels are computed and these are used in extensions of the Lüscher formalism to determine infinite volume scattering amplitudes. Working in the approximation where charmannihilation is forbidden, the ground state $\chi_{c0}(1P)$ and $\chi_{c2}(1P)$ states are stable. Below 4000 MeV we find a single $\chi_{c0}$ and a single $\chi_{c2}$ resonance, both stronglycoupled to several decay channels consisting of pairs of opencharm mesons. Both resonances are found on the closest unphysical sheet just below $4000$ MeV with widths of $\approx$ 60 MeV. The largest couplings are to the closed $D^\ast\bar{D}^\ast$ channels in $S$wave, but several opencharm channels are also found to be large and significant in both cases. All closedcharm channels are found to be approximately decoupled. No additional states are found beyond what would be expected from quarkmodellike $c\bar{c}$ excitations.
Tuesday
22 Oct/24
16:00

18:00
(Europe/Zurich)
Scalar and Tensor Charmonium Resonances from lattice QCD
Where:
4/2037 at CERN