Il Nuovo Cimento A (1965-1970)

, Volume 107, Issue 2, pp 271–278 | Cite as

Multi-Higgs doublet model: Can it account for ℓ+γγ events?

  • G. Cvetič
  • M. Nowakowski
  • Yue-Liang Wu


Motivated by recent experiments at LEP (Z →ℓ+ γγ, withMγγ-59 GeV), we examine the possibility that such events are explained by a Bjorken process with a resonant Higgs (Mho ≏59 GeV) decaying to γγ. We investigate theN-doublet-Higgs model withoutCP violation. Under the simplifying assumption that(N-k) doublets (k≥ 1) decouple from the fermion sector, we could only explain the observed events if: i)(N- 1) ≥ 2 and ii) the masses of the corresponding(N- 1) neutral scalars are either completely or almost degenerate,i.e. the decay Z →ℓ+ γγ proceeds now via several overlapping resonances. Such a scenario would require fine tuning. Furthermore, the deficit of the observed decays Z → → vvγ, qqγγ (atMγγ∽59 GeV) indicates that one either has to go beyond simple extensions of the minimal standard model, or one has to wait for more experimental data.

PACS 12.90

Miscellaneous theoretical ideas and models 

PACS 12.15.Ji

Applications of electroweak models to specific processes 


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Copyright information

© Società Italiana di Fisica 1994

Authors and Affiliations

  • G. Cvetič
    • 1
  • M. Nowakowski
    • 1
  • Yue-Liang Wu
    • 1
  1. 1.Institut für PhysikUniversitÄt DortmundDortmund 50Germany

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