Within a multi-channel formulation of ππ scattering, we investigate the use of the finite-volume Hamiltonian approach to resolve scattering observables from lattice QCD spectra. The asymptotic matching of the well-known L\"uscher formalism encodes a unique finite-volume spectrum. Nevertheless, in many practical situations, such as coupled-channel systems, it is advantageous to interpolate isolated lattice spectra in order to extract physical scattering parameters. Here we study the use of the Hamiltonian framework as a parameterisation that can be fit directly to lattice spectra. We find that with a modest amount of lattice data, the scattering parameters can be reproduced rather well, with only a minor degree of model dependence.
@article{arxiv.1402.4868,
title = {Finite-volume Hamiltonian method for coupled channel interactions in lattice QCD},
author = {Jia-Jun Wu and T. -S. H. Lee and A. W. Thomas and R. D. Young},
journal= {arXiv preprint arXiv:1402.4868},
year = {2014}
}