Studying trilinear gauge couplings at LEP2 using optimal observables

Abstract

We study the sensitivity of the processes `e+ e- -> lepton (l) neutrino (v) quark (u) antiquark (d)' at LEP2 energies on the non-standard trilinear gauge couplings (TGC), using the optimal observables method. All relevant leading logarithmic corrections to the tree-order cross section, as well as experimental resolution effects have been studied. Taking into account correlations among the different TGC parameters we show that the limits on the TGC can reach the level of 0.15~(1sd) at 161 GeV with 100 pb$^{-1}$, a challenge for the first LEP2 phase. At higher energies this can be improved drastically, reaching the level of 0.02~(1sd).