The European Physical Journal C - Particles and Fields

, Volume 13, Issue 4, pp 553–572

Tests of the standard model and constraints on new physics from measurements of fermion-pair production at 189 GeV at LEP

Authors

  • The OPAL Collaboration
  • G. Abbiendi et al.
    • Dipartimento di Fisica dell' Università di Bologna and INFN, I-40126 Bologna, Italy
Experimental physics

DOI: 10.1007/s100520000315

Cite this article as:
The OPAL Collaboration & Abbiendi et al., G. Eur. Phys. J. C (2000) 13: 553. doi:10.1007/s100520000315

Abstract.

Cross-sections and angular distributions for hadronic and lepton pair final states in \({\rm e^+e^-}\) collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The results are used to measure the energy dependence of the electromagnetic coupling constant \(\alpha_{\rm em}\), and to place limits on new physics as described by four-fermion contact interactions or by the exchange of a new heavy particle such as a sneutrino in supersymmetric theories with R-parity violation. A search for the indirect effects of the gravitational interaction in extra dimensions on the \(\mu^+\mu^-\) and \(\tau^+\tau^-\) final states is also presented.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000