An analysis of the data collected in 1997 and 1998 with the DELPHI detector at e+e- collision energies close to 183 and 189 GeV was performed in order to extract the hadronic and leptonic fermion-pair cross-sections, as well as the leptonic forward-backward asymmetries and angular distributions. The data are used to put limit on contact interactions between fermions, the exchange of R-parity violating SUSY sneutrinos, Z' bosons and the existence of gravity in extra dimensions.
Abreu, P., Cortina Gil, E., & DELPHI Collaboration. (2000). Measurement and Interpretation of Fermion-Pair Production at LEP Energies of 183 and 189 GeV. Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics, 485, 45-61. https://doi.org/10.1016/S0370-2693(00)00675-4 (Original work published 2000)