Charmonium Production at FNAL-E835 - Triplet P States

Abstract

Fermilab experiment E835 has done an extensive set of studies on charmonium triplet P states. The most precise measurements on mass and total width come indeed from charmonium spectroscopy by direct formation of $c\bar{c}$ states in $\bar{p}p$ annihilations. Results on both partial widths and higher multipoles radiative transitions ${\chi }_{cJ}\to J/\psi \gamma \to \gamma e^{+}{e}^{-}$ are given, together with the $\gamma \gamma$ widths of ${\chi }_{c0}$ and ${\chi }_{c2}$. For the first time in hadronic charmonium production, hadronic annihilation channels (${\pi }^0{\pi }^0$ and $\eta \eta$) have been clearly identified at the ${\chi }_{c0}$ resonance.

6 pages, 5 figures, 1 table, conference