We have studied the 3PJ (χc) states of charmonium in formation by antiproton-proton annihilations in experiment E835 at the Fermi lab Antiproton Source. We report new measurements of the mass, width, and B(χcJ → p̄p) Γ (χcJ → J/ψ + anything) for the χc1 and χc2 by means of the inclusive reaction p̄p → χcJ → J/ψ + anything → (e+e-) + anything. Using the subsample of events where χcJ → γ + (e+e-) is fully reconstructed, we derive B(χcJ → p̄p) Γ (χcJ → J/ψ + γ). We summarize the results of the E760 (updated) and E835 measurements of mass, width and B (χcJ → p̄p) Γ (χcJ → J/ψ + γ) (J = 0, 1, 2) and discuss the significance of these measurements.
ASJC Scopus subject areas
- Nuclear and High Energy Physics