Study of fermion pair production in e+e- collisions at 130-183 GeV

The cross sections and forward-backward asymmetries of hadronic and leptonic events produced in e+e- collisions at centre-of-mass energies from 130 to 183 GeV are presented. Results for e+e-, μ+μ-, τ+τ-, qq̄. bb̄ and cc̄ production show no significant deviation from the Standard Model predictions. This enables constraints to be set upon physics beyond the Standard Model such as four-fermion contact interactions, leptoquarks. Z′ bosons and R-parity violating squarks and sneutrinos. Limits on the energy scale Λ of e+e-ff̄ contact interactions are typically in the range from 2 to 10 TeV. Limits on R-parity violating sneutrinos reach masses of a few hundred GeV/c2 for large values of their Yukawa couplings.