Speaker
Dr
David Wilson
(for the Hadron Spectrum Collaboration)
Description
The excited states in hadron physics are seen as resonances in the scattering of light stable states in QCD, like $\pi$, $K$ and $\eta$ mesons. Many excited states also decay into multiple final states, necessitating coupled-channel analyses. Recently it has become possible to obtain coupled-channel scattering amplitudes using lattice QCD. Using a large diverse basis of operators we are able to obtain a reliable finite volume spectrum describing, for example, the $\pi\eta$, $K\bar{K}$ coupled system. Utilising the finite volume formalism proposed by Luescher and extended by several others, we are able to describe the spectra from each lattice symmetry group and this enables constraints to be derived for S, P and D-wave scattering. In S-wave we find a resonant scattering amplitude containing a pole on an unphysical sheet close to $K\bar{K}$ threshold, with some similarities to the $a_0$(980) seen in experiment. Possible future extensions, and results from related studies such as the $\rho$ resonance at multiple pion masses, and $\pi K$ scattering will also be presented.
Primary author
Dr
David Wilson
(for the Hadron Spectrum Collaboration)
