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

Journal Article · Mon Feb 01 00:00:00 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), Vol. 47:3; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

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