Measurement of the resonance parameters of the X1(1(3)P(1)) and X2(1(3)P(2)) states of charmonium formed in antiproton-proton annihilations

We have studied the P-3(J) (chi(C)) states of charmonium in formation by antiproton-proton annihilations in experiment E835 at the Fermilab Antiproton Source. We report new measurements of the mass, width, and B(chi(cJ) -> (p) over barp)Gamma(chi(cJ) -> J/psi + anything) for the chi(c1) and chi(c2) by means of the inclusive reaction (p) over barp -> X-cJ -> J/psi + anything -> (e(+)e(-)) + anything. Using the sub-sample of events where chi(cJ) -> gamma + J/psi -> y + (e(+)e(-)) is fully reconstructed, we derive B(chi(cJ) -> (p) over barp)Gamma(chi(cJ) -> J/psi + gamma). We summarize the results of the E760 (updated) and E835 measurements of mass, width and B(chi(cJ) -> (p) over barp)Gamma(chi(cJ) -> J/psi + gamma) (J = 0, 1, 2) and discuss the significance of these measurements. (c) 2005 Elsevier B.V. All rights reserved.