Abstract: Fermilab experiment E835 has studied Charmonium produced in annihilation using a gas jet hydrogen target, the virtually monoenergetic stochastically cooled antiproton beam and a large acceptance electromagnetic calorimeter. During the last data taking, the state has been observed in the final states (and ). Although the resonant amplitude is an order of magnitude smaller than that of the non-resonant continuum production of , an enhanced interference signal is evident. A partial wave expansion is used to extract physics parameters. A brief introduction to charmonium spectroscopy will also be given.