Chiral extrapolations and exotic meson spectrum

We examine the chiral corrections to exotic meson masses calculated in lattice QCD. In the soft pion limit we find that corrections from virtual, closed channels lead to strong non-linear behavior which has been found in other hadronic systems. We find the resulting mass shifts to be as large as 100 MeV and therefore large corrections to the predictions of exotic meson masses based on linear extrapolations to the chiral limit are expected. Furthermore, by considering a class of phenomenologically successful hybrid meson models we show that this behavior is not altered by contributions from open decay channels.