Eur. Phys. J. C (2003) 30: 395-407
https://doi.org/10.1140/epjc/s2003-01288-y

theoretical physics

Polarisation in sfermion decays: determining $\tan\beta$ and trilinear couplings

¹ Skobeltsyn Institute of Nuclear Physics, Moscow State University, 119992, Moscow, Russia
² DESY, Deutsches Elektronen-Synchrotron, 22603, Hamburg, Germany
³ Rheinisch-Westfälische Technische Hochschule, 52074, Aachen, Germany
⁴ IPPP, University of Durham, DH1 3LE, Durham, UK
⁵ DESY, Deutsches Elektronen-Synchrotron, 15738, Zeuthen, Germany

Abstract

The basic parameters of supersymmetric theories can be determined at future e ⁺ e ^- linear colliders with high precision. We investigate in this report how polarisation measurements in $\tilde{\tau}$ and $\tilde{t}$ or $\tilde{b}$ decays to $\tau$ leptons and t quarks plus neutralinos or charginos can be used to measure $\tan\beta$ (in particular for large values) and to determine the trilinear couplings $A_{\tau}$, A _t and A _b in sfermion pair production.