Advertisement

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
Article
  • 14 Downloads

Summary

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 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    L3 Collaboration:Phys. Lett. B,295, 337 (1992).CrossRefADSGoogle Scholar
  2. [2]
    M. Pohl: talk given in Dortmund, 1 December 1992.Google Scholar
  3. [3]
    J. F. Gunion, H. H. Haber, G. L. Kane andS. Dawson:The Higgs Hunter’s Guide (Addison-Wesley, Reading, Mass., 1990), p. 56.Google Scholar
  4. [4]
    G. Keller andD. Wyler:Nucl Phys. B,274, 410 (1986).CrossRefADSGoogle Scholar
  5. [5]
    Z. Kunszt and W. J. Stirling: inLarge Hadron Collider Workshop, Aachen, 1990, edited by G. Jarlskog and D. Rein, CERN 90-10, ECFA 90–133, Vol. II, p. 428.Google Scholar
  6. [6]
    V. Barger, N. G. Deshpande, J. L. Hewett and T. G. Rizzo: Argonne National Laboratory preprint ANL-HEP-PR-92-102, November 1992Google Scholar
  7. [7]
    U. Amaldi: private communication (DELPHI Note:A Study of Z Decays into Two Leptons and Two Photons Using the DELPHIDetector, DELPHI Collaboration, CERN, 18 December 1992).Google Scholar
  8. [8]
    Y.-H. Chang: talk presented at theXXVIII Rencontres de Moriond, March, 1993. Google Scholar

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

Personalised recommendations