For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair production in collisions on the full data set above the Z pole. A combined analysis of the Bhabha scattering measurements is performed to search for effects of contact interactions. In the case of two axial-vector currents the best fit to the data is 2.6 standard deviations away from the standard model expectation, corresponding to an energy scale for contact interactions. For other models no statistically significant deviations are observed, and the data are used to set lower limits at 95% confidence level on the contact interaction scales ranging from 8.2 to 21.3 TeV, depending on the helicity structure.
- Received 18 April 2001
- Revised 29 June 2001
- Published 5 September 2001
© 2001 The American Physical Society