Supersymmetric grand unified theories: Two-loop evolution of gauge and Yukawa couplings

Journal Article · Sun Jan 31 23:00:00 EST 1993 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.47.1093· OSTI ID:6819098

Barger, V; Berger, M S; Ohmann, P ^[1]

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1. Physics Department, University of Wisconsin, Madison, Wisconsin 53706 (United States)

We make a numerical study of guage and Yukawa unification in supersymmetric grand unified models and examine the quantitative implications of fermion mass [ital Ansa]$[ital iuml]---[ital tze] at the grand unified scale. Integrating the renormalization group equations with [alpha][sub 1]([ital M][sub [ital Z]]) and [alpha][sub 2]([ital M][sub [ital Z]]) as inputs, we find [alpha][sub 3]([ital M][sub [ital Z]])[congruent]0.111(0.122) for [ital M][sub SUSY]=[ital m][sub [ital t]] and [alpha][sub 3]([ital M][sub [ital Z]])[congruent]0.106(0.116) for [ital M][sub SUSY]=1 TeV at one-loop (two-loop) order. Including [ital b] and [tau] Yukawa couplings in the evolution, we find an upper limit of [ital m][sub [ital t]][approx lt]200 GeV from Yukawa unification. For given [ital m][sub [ital t]][approx lt]175 GeV, there are two solutions for [beta]: one with tan[beta][gt][ital m][sub [ital t]]/[ital m][sub [ital b]], and one with sin[beta][congruent]0.78([ital m][sub [ital t]]/150 GeV). Taking a popular [ital Ansatz] for the mass matrices at the unified scale, we obtain a lower limit on the top-quark mass of [ital m][sub [ital t]][approx gt]150(115) GeV for [alpha][sub 3]([ital M][sub [ital Z]])=0.11(0.12) and an upper limit on the supersymmetry parameter tan[beta][approx lt]50 if [alpha][sub 3]([ital M][sub [ital Z]])=0.11. The evolution of the quark mixing elements is also evaluated.

• DOE Contract Number: AC02-76ER00881
• OSTI ID: 6819098
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 47:3; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662120 -- General Theory of Particles & Fields-- Symmetry
Conservation Laws
Currents & Their Properties-- (1992-)
662210* -- Specific Theories & Interaction Models
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COUPLING
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
GAUGE INVARIANCE
GRAND UNIFIED THEORY
INVARIANCE PRINCIPLES
MASS
MATHEMATICAL MODELS
MATRIX ELEMENTS
NUCLEAR POTENTIAL
PARTICLE MODELS
POSTULATED PARTICLES
POTENTIALS
Pa
Particle Systematics-- Unified Theories & Models-- (1992-)
QUARKS
RENORMALIZATION
STANDARD MODEL
SUPERSYMMETRY
SYMMETRY
TOP PARTICLES
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES
YUKAWA POTENTIAL