E835 at FNAL: Charmonium Spectroscopy in $\bar p p$ Annihilations

Abstract

I present preliminary results on the search for $h_c$ in its $η_cγ$ and $J/ψπ^0$ decay modes. We observe an excess of η_cγ$ events near 3526 MeV that has a probability ${\cal P} \sim 0.001$ to arise from background fluctations. The resonance parameters are $M=3525.8 \pm 0.2 \pm 0.2 $MeV, $Γ\leq$ 1 MeV, and $10.6\pm 3.7\pm3.4(br) < Γ_{\bar{p}p}B_{η_cγ} < 12.8\pm 4.8\pm4.5(br) $eV. We find no event excess within the search region in the $J/ψπ^0$ mode.