sin ^{2}θ_{W} ( M_{Z}) in the MSSM and unification of couplings
Abstract
We calculate sin ^{2}θ( M_{Z}) in the MSSM in terms of α_{EM}, GF, m_{t}, tan β and SUSY mass parameters with the same accuracy as the present calculations of sin ^{2}θ( M_{z}) in the SM. We compare the results with the standard leading logarithmic approximation used for SUSY threshold corrections and find important differences in the case of light sparticles. We give approximate formulae connecting coupling constants in the SM and in the MSSM and comment on process dependence of such formulae. The obtained values of the MSSM couplings α_{i}( M_{z}) are used to investigate gauge coupling unification. The interplay between the supersymmetric and GUT thresholds in achieving unification for the coupling constants in the range of the experimentally acceptable values is quantified. In the minimal SUSY SU(5) model, our nonlogarithmic corrections lower the predicted value of the Higgs triplet mass.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1995
 DOI:
 10.1016/05503213(95)00033O
 arXiv:
 arXiv:hepph/9411233
 Bibcode:
 1995NuPhB.439...23C
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 30 pages, standard LaTeX