eta_c Production at the Tevatron: A test of NRQCD

We use NRQCD to predict the cross section for ${\eta }_c$ production at the Tevatron. The non-perturbative matrix elements required are obtained, using heavy-quark symmetry, from the matrix elements determined from the CDF $J\mathrm{/}\psi$ data. Our numbers are, therefore, predictions of NRQCD and provide a very good test of it. Even after taking into account the small branching ratio of the ${\eta }_c$ into two photons, a substantial rate for the production of this resonance at the Tevatron is expected.