Eur. Phys. J. C 20, 563-584 (2001)
DOI: 10.1007/s100520100679
Chargino and neutralino decays revisited
A. Djouadi1, Y. Mambrini1, 2 and M. Mühlleitner11 Laboratoire de Physique Mathématique et Théorique, UMR5825-CNRS, Université de Montpellier II, 34095 Montpellier Cedex 5, France
2 CEA/DIF/DPTA/SPN, B.P. 12, 91680 Bruyères le Châtel, France
(Received: 12 April 2001 / Published online: 8 June 2001 -© Springer-Verlag / Società Italiana di Fisica 2001)
Abstract
We perform a comprehensive analysis of the decays of charginos
and
neutralinos in the minimal supersymmetric standard model where
the neutralino
is assumed to be the lightest supersymmetric particle.
We focus, in
particular, on the three-body decays of the next-to-lightest
neutralino and
the lightest chargino into the lightest neutralino and fermion-antifermion
pairs and include vector boson, Higgs boson and sfermion exchange
diagrams,
where in the latter contribution the full mixing in the third
generation is
included. The radiative corrections to the heavy fermion and
SUSY particle
masses will also be taken into account. We present complete analytical
formulae
for the Dalitz densities and
the integrated partial decay widths in the massless
fermion case, as well as the expressions of the differential
decay widths
including the masses of the final fermions and the polarization
of the decaying
charginos and neutralinos. We then discuss these decay modes,
in particular
in scenarios where the parameter
is large and in
models without
universal gaugino masses at the grand unification scale, where
some new decay
channels, such as decays into gluinos and
pairs,
open up.
© Società Italiana di Fisica, Springer-Verlag 2001