Using CLEO data, we study the production of the antideuteron, d̄, in Υ(nS) resonance decays and the nearby continuum. The branching ratios obtained are Bdir(Υ(1S)→d̄X)=(3.36±0.23±0.25) ×10-5, B(Υ(1S)→d̄X)=(2.86±0.19±0.21) ×10-5, and B(Υ(2S)→d̄X)=(3.37±0.50±0.25) ×10-5, where the "dir" superscript indicates that decays produced via reannihilation of the bb̄ pair to a γ* are removed from both the signal and the normalizing number of Υ(1S) decays in order to isolate direct decays of the Υ(1S) to ggg, ggγ. Upper limits at 90% C.L. are given for B(Υ(4S)→d̄X)<1.3×10-5, and continuum production σ(e+e-→d̄X)<0.031pb. The Υ(2S) data is also used to extract a limit on χbJ→d̄X. The results indicate enhanced deuteron production in ggg, ggγ hadronization compared to γ*→qq̄. Baryon number compensation is also investigated with the large Υ(1S)→d̄X sample.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - 2007|