Model independent constraints on contact interactions from LEP2

Abstract

We quantitatively discuss the possibility of deriving model-independent constraints on the general four-fermion contact interaction couplings, from the currently available data on the two-fermion production processes $e^+e^-\toμ^+μ^-$, $b\bar{b}$ and $c\bar{c}$ with unpolarized initial beams. The method is essentially based on particular, simple, combinations of the measured total cross section and forward-backward asymmetry that allow partial separation of the helicity cross sections, and the combination of experimental data obtained at the different energies of TRISTAN, LEP1 and LEP2.