Search for promptly produced heavy quarkonium states in hadronic Z decays

Collaboration
Oct, 1995
20 pages
Published in:
  • Z.Phys.C 69 (1996) 575-584
Report number:
  • CERN-PPE-95-145
Experiments:

Citations per year

199620032010201720245601
Abstract: (Springer)
A search has been made for direct production of heavy quarkonium states in more than 3 million hadronic Z0 decays in the 1991–1994 DELPHI data. Prompt J/ψ, ψ(2S) and Υ candidates have been searched for through their leptonic decay modes using criteria based on the kinematics and decay vertex positions. New upperlimits are set at the 90% confidence level for Br(Z0 → (QQ) X)/Br (Z0 → hadrons) for various strong production mechanisms of J/ψ and Υ these range down to 0.9 × 10−4. The limits are set in the presence of a small excess (∼ 1% statistical probability of a background fluctuation) in the sum of candidates from prompt J/ψ, ψ(2S), Υ(1S),Υ(2S) and Υ(3S) relative to the estimated background.
  • electron positron: colliding beams
  • colliding beams: electron positron
  • electron positron: annihilation
  • annihilation: electron positron
  • Z0: electroproduction
  • electroproduction: Z0
  • Z0: hadronic decay
  • hadronic decay: Z0
  • quarkonium: heavy
  • quarkonium: direct production