Determining SUSY Parameters in Chargino Pair-Production in $e^{+}{e}^{-}$ Collisions

Abstract

In most supersymmetric theories, charginos ${\tilde{\chi }}_{1,2}^{\pm }$, mixtures of charged color-neutral gauginos and higgsinos, belong to the class of the lightest supersymmetric particles. They are easy to observe at $e^{+}{e}^{-}$ colliders. By measuring the total cross sections and the left-right asymmetries with polarized electron beams in $e^{+}{e}^{-}\to {\tilde{\chi }}_i^{-}{\tilde{\chi }}_j^{+}[i,j=1,2]$, the chargino masses and the gaugino-higgsino mixing angles can be determined. From these observables the fundamental SUSY parameters can be derived: the SU(2) gaugino mass $M_2$, the modulus $|\mu |$ and $\cos {\Phi }_{\mu }$ of the higgsino mass parameter, and $\tan \beta =v_2/v_1$, the ratio of the vacuum expectation values of the two neutral Higgs doublet fields. The solutions are unique; the CP-violating phase ${\Phi }_{\mu }$ can be determined uniquely by analyzing effects due to the normal polarization of the charginos.

Comments: 20 pages, 4 figures, uses axodraw.sty