Measurements of J/psi --> p \bar{p}
Abstract
Description
The process J/ψ--> p \bar{p} is studied using 57.7 X 10^6 J/ψevents collected with the BESII detector at the Beijing Electron Positron Collider. The branching ratio is determined to be Br(J/ψ--> p \bar{p})=(2.26 +- 0.01 +- 0.14) X 10^{-3}, and the angular distribution is well described by \frac{dN}{d cosθ_p}=1+α\cos^2θ_p with α= 0.676 +- 0.036 +- 0.042, where θ_p is the angle between the proton and beam directions. The value of αobtained is in good agreement with the predictions of first-order QCD.
6 pages, 2 figures, RevTex4, Submitted to Phys.Lett.B
6 pages, 2 figures, RevTex4, Submitted to Phys.Lett.B