Published April 1, 2000 | Version v1
Journal article

Implications of LEP and SLD data for new physics in Zbb(bar sign) couplings

  • 1. Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States)
  • 2. Institute of Theoretical Physics, Academia Sinica, Beijing 100080, (China)
  • 3. Department of Physics, Tohoku University, Aoba-ku, Sendai 980-8578, (Japan)
  • 4. Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)

Description

The combined CERN LEP and SLAC Large Detector (SLD) data on the bb(bar sign) forward-backward asymmetry from the Z-pole measurements may imply the presence of new physics in the Zbb(bar sign) couplings. In general, the effect of new physics can be parametrized by SUC(3)xSUL(2)xUY(1) invariant higher dimensional operators. By fitting the recently announced LEP and SLD data on Ab and Rb, the size of the coupling strengths of these operators can be determined. We also found that the new physics operators can be divided into two types, depending on their Higgs field content. The ones involving the Higgs field have very mild effects at higher energy colliders, while the other type which do not contain the Higgs field can show significantly large effects on bb(bar sign) production at LEP II, tt(bar sign) production at the NLC and single top quark production at the Fermilab Tevatron. The preliminary data from the LEP II measurements disfavor the second type of operators. (c) 2000 The American Physical Society

Additional details

Publishing Information

Journal Title
Physical Review. D, Particles Fields
Journal Volume
61
Journal Issue
7
Journal Page Range
p. 075007-075007.7
ISSN
0556-2821
CODEN
PRVDAQ