Supersymmetric {ital b}-{tau} unification, gauge unification, and fixed points
- Sektion Physik der Universitaet Muenchen, Lehrstuhl Prof. Wess, Theresienstrasse 37, D-80333 Muenchen (Germany)
The equality assumption of the {ital b} and {tau} Yukawa couplings at the grand-unification scale can strongly constrain the allowed parameter space of supersymmetric models. We examine the constraints in the case that there is a discrepancy {approx_gt}10{percent} in the gauge coupling unification assumption (which necessarily implies large perturbations at the grand scale). The constraints are shown to diminish in that case [most significantly so if {alpha}{sub {ital s}}({ital M}{sub {ital Z}}){approx_equal}0.11]. In particular, the requirement that the {ital t} Yukawa coupling {ital h}{sub {ital t}} is near its quasifixed point may not be necessary. We discuss the colored-triplet threshold as a simple example of a source for the discrepancies, and comment on its possible implications. In addition, we point out that supersymmetric (as well as unification-scale) threshold corrections to {ital h}{sub {ital t}} shift the fixed-point curve in the {ital m}{sub {ital t}}-tan{beta} plane. The implications for the prediction of the Higgs boson mass are briefly discussed. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 385360
- Journal Information:
- Physical Review, D, Journal Name: Physical Review, D Journal Issue: 7 Vol. 54; ISSN PRVDAQ; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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