G. Abbiendi et al., TESTS OF THE STANDARD MODEL AND CONSTRAINTS ON NEW PHYSICS FROM MEASUREMENTS OF FERMION-PAIR PRODUCTION AT 183 GEV AT LEP, The European Physical Journal. C: Particles and Fields, 6(1), 1999, pp. 1-18
Cross-sections for hadronic. bl; and lepton pair final states in e(+)e
(-) collisions at. root s=183 GeV, measured with the OPAL detector at
LEP, are presented and compared with the predictions of the Standard M
odel. Forward-backward asymmetries for the leptonic final state:! have
also been measured. Cross-sections and asymmetries are also presented
for data recorded in 1997 at root s=130 and 136 GeV. The results are
used to measure the energy dependence of the electromagnetic coupling
constant alpha(em), and to place limits on new physics as described by
four-fermion contact interactions or by the exchange of a new heavy p
article such as a leptoquark, or of a squark or sneutrino in supersymm
etric theories with R-parity violation.