Search for Decays of the Z0\Z^0 Into a Photon and a Pseudoscalar Meson

Collaboration
Feb, 1990
9 pages
Published in:
  • Phys.Lett.B 241 (1990) 635-643
  • Published: 1990
Report number:
  • CERN-EP/90-23
Experiments:

Citations per year

19901991199219936702
Abstract: (Elsevier)
A search is reported for decays of the Z 0 into π 0 γ , ηγ and η ′ (958) γ in e + e − collisions using data collected during a scan around the Z 0 mass. In order to search for π 0 γ final states, in which the two photons from the π 0 decay are unresolved, the production of pairs of high-energy electromagnetic clusters is studied. The data are compared with the expectations from the pure QED process e + e − → γγ , and a 95% confidence level upper limit on the branching ratio of the Z 0 into π 0 γ of 4.9 × 10 −4 is derived. For η′γ, the decay modes of the mesons that contain two charged particles are largely free from QED background. These modes are used to place upper limits of 4.6 × 10 −4 and 2.2 × 10 −4 on the corresponding branching ratios of the Z 0 .
  • electron positron: colliding beams
  • colliding beams: electron positron
  • electron positron: annihilation
  • annihilation: electron positron
  • Z0: electroproduction
  • electroproduction: Z0
  • Z0: radiative decay
  • radiative decay: Z0
  • pseudoscalar meson: production
  • production: pseudoscalar meson