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arXiv · hep-ph/9503422

Precise Predictions for the Masses and Couplings in the Minimal Supersymmetric Standard Model

Jonathan Bagger·Konstantin Matchev·Damien Pierce
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Abstract

We present selected results of our program to determine the masses, gauge couplings, and Yukawa couplings of the minimal supersymmetric model in a full one-loop calculation. We focus on the precise prediction of the strong coupling alpha_s(M_Z) in the context of supersymmetric unification. We discuss the importance of including the finite corrections and demonstrate that the leading-logarithmic approximation can significantly underestimate alpha_s(M_Z) when some superpartner masses are light. We show that if GUT thresholds are ignored, and the superpartner masses are less than about 500 GeV, the prediction for alpha_s(M_Z) is quite large. We impose constraints from nucleon decay experiments and find that minimal SU(5) GUT threshold corrections increase alpha_s(M_Z) over most of the parameter space. We also consider the missing-doublet SU(5) model and find that it predicts preferred values for the strong coupling, even for a very light superpartner spectrum. We briefly discuss predictions for the bottom-quark mass in the small tan beta region.

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Jonathan Bagger, Konstantin Matchev, Damien Pierce. 1995-03-24. Precise Predictions for the Masses and Couplings in the Minimal Supersymmetric Standard Model. https://arxiv.org/abs/hep-ph/9503422

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