The resonance parameters of the χc0, the 13P0 state of charmonium, have been measured at the Fermilab Antiproton Accumulator in the reaction pp → χc0 → γJ/ψ → γ(e+e-). A large data sample collected during the year 2000 run yields the results: M(χc0) = 3415.4±0.4±0.2 MeV/c2, γ(χc0) = 9.8±1.0±0.1 MeV, B(χc0 → pp) × B(χc0 → γJ/ψ) × B(J/ψ → (e+e-)) = (1.61±0.11±0.08) × 10-7. Taking B(χc0 → γJ/ψ) and B(J/ψ → e+e-) from the literature, we obtain B(χc0 → pp) = (4.1±0.3-0.9+16) × 10-4 and γ(χc0 → pp) = (4.0±0.4-0.9+1.6) keV.
|Original language||English (US)|
|Number of pages||6|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - May 9 2002|
Bibliographical noteFunding Information:
The authors thank the staff at their respective institutions for their support. They particularly wish to acknowledge the work of the Antiproton Source Department of the Fermilab Beams Division in developing the new beam deceleration ramps. This research was supported by the US Department of Energy and the Italian Istituto Nazionale di Fisica Nucleare.