Probing Contact Interactions at High Energy Lepton Colliders

Abstract

Fermion compositeness and other new physics can be signalled by the presence of a strong four-fermion contact interaction. Here we present a study of $\ell \ell qq$ and $\ell \ell {\ell }^{\prime }{\ell }^{\prime }$ contact interactions using the reactions: ${\ell }^{+}{\ell }^{-}\to {\ell }^{\prime +}{\ell }^{\prime -},b\bar{b},c\bar{c}$ at future $e^{+}{e}^{-}$ linear colliders with $\sqrt{s}=0.5-5$ TeV and $\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ colliders with $\sqrt{s}=0.5,4$ TeV. We find that very large compositeness scales can be probed at these machines and that the use of polarized beams can unravel their underlying helicity structure.

12 pg, to appear in the {\it Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics - Snowmass96}, Snowmass, CO, 25 June - 12 July, 1996