We report on the extraction of an excited spectrum of isoscalar mesons using lattice QCD. Calculations on several lattice volumes are performed with a range of light quark masses corresponding to pion masses down to about 400 MeV. The distillation method enables us to evaluate the required disconnected contributions with high statistical precision for a large number of meson interpolating fields. We find relatively little mixing between light and strange in most JPC channels; one notable exception is the pseudoscalar sector where the approximate SU(3)F octet, singlet structure of the {\eta}, {\eta}' is reproduced. We extract exotic JPC states, identified as hybrid mesons in which an excited gluonic field is coupled to a color-octet qqbar pair, along with non-exotic hybrid mesons embedded in a qqbar-like spectrum.
@article{arxiv.1309.2608,
title = {Toward the excited isoscalar meson spectrum from lattice QCD},
author = {Jozef J. Dudek and Robert G. Edwards and Peng Guo and Christopher E. Thomas},
journal= {arXiv preprint arXiv:1309.2608},
year = {2013}
}