DOI 10.1007/s100529800993
Decoupling of supersymmetric particles
A. Dobado1 - M.J. Herrero2 - S. Peñaranda2
1 Departamento de Física Teórica,
Universidad Complutense de Madrid,
E-28040 Madrid, Spain
2 Departamento de Física Teórica,
Universidad Autónoma de Madrid,
Cantoblanco, E-28049 Madrid, Spain
Received: 27 March 1998 / Published online: 5 October 1998
Abstract
The possibility of a heavy supersymmetric spectrum at the Minimal Supersymmetric Standard Model is
considered and the decoupling from the low energy electroweak scale is analyzed in detail. The
formal proof of decoupling of supersymmetric particles from low energy physics is stated in terms
of the effective action for the particles of the Standard Model that results by integrating out
all the sparticles in the limit where their masses are larger than the electroweak scale. The
computation of the effective action for the standard electroweak gauge bosons 
and
is performed by integrating out all the squarks, sleptons, charginos and neutralinos to
one-loop. The Higgs sector is not considered in this paper. The large sparticle masses limit is
also analyzed in detail. Explicit analytical formulae for the two-point functions of the electroweak gauge
bosons to be valid in that limit are presented. Finally, the decoupling of sparticles in the S, T and U
parameters is studied analitically. A discussion on how the decoupling takes place in terms of both the
physical sparticle masses and the non-physical mass parameters as the 
-parameter and the
soft-breaking parameters is included.
Copyright Springer-Verlag
