  The decay rates of the XYZ exotics discovered in the heavy quarkonium sector
are crucial observables for identifying the nature of these states. Based on
the framework of nonrelativistic effective field theories, we calculate the
rates of semi-inclusive decays of heavy quarkonium hybrids into conventional
heavy quarkonia. We compute them at leading and subleading power in the inverse
of the heavy-quark mass, extending and updating previous results. We compare
our predictions with experimental data of inclusive decay rates for candidates
of heavy quarkonium hybrids.
