2022 Impact factor 4.4
Particles and Fields
Eur. Phys. J. C 8, 669-677
DOI 10.1007/s100529901093

Determining SUSY parameters in chargino pair-production in e+e- collisions

S.Y. Choi1 - A. Djouadi2 - H.S. Song3 - P.M. Zerwas4

1 Korea Institute for Advanced Study, 207-43, Cheongryangri-dong, Dongdaemun-gu, Seoul 130-012, Korea
2 Phys. Math. et Théorique, Université Montpellier II, F-34095 Montpellier, France
3 Center for Theoretical Physics and Department of Physics, Seoul National University, Seoul 151-742, Korea
4 DESY, Deutsches Elektronen-Synchrotron, D-22603 Hamburg, Germany

Received: 3 December 1998 / Published online: 27 April 1999

In most supersymmetric theories, charginos $\tilde{\chi}^\pm_{1,2}$, 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 $e^+e^- \rightarrow \tilde{\chi}_i^- \tilde{\chi}_j^+ \, \, [i,j=1,2]$,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 M2, the modulus $\vert\mu\vert$ 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.

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