Large ([ital g][minus]2)[sub [mu]] in SU(5)[times]U(1) supergravity models

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.49.366· OSTI ID:5340472

Lopez, J L; Nanopoulos, D V; Wang, X ^[1]

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1. Center for Theoretical Physics, Department of Physics, Texas A M University, College Station, Texas 77843-4242 (United States) Astroparticle Physics Group, Houston Advanced Research Center (HARC), The Woodlands, Texas 77381 (United States) CERN, Theory Division, 1211 Geneva 23 (Switzerland)

We compute the supersymmetric contribution to the anomalous magnetic moment of the muon within the context of SU(5)[times]U(1) supergravity models. The largest possible contributions to [ital a][sub [mu]][sup SUSY] occur for the largest allowed values of tan[beta] and can easily exceed the present experimentally allowed range, even after the CERN LEP lower bounds on the sparticle masses are imposed. Such tan[beta] enhancement implies that [ital a][sub [mu]][sup SUSY] can greatly exceed both the electroweak contribution ([approx]1.95[times]10[sup [minus]9]) and the present hadronic uncertainty ([approx][plus minus]1.75[times]10[sup [minus]9]). Therefore, the new E821 Brookhaven experiment (with an expected accuracy of 0.4[times]10[sup [minus]9]) should explore a large fraction (if not all) of the parameter space of these models, corresponding to slepton, chargino, and squarks masses as high as 200, 300, and 1000 GeV, respectively. Moreover, contrary to popular belief, the [ital a][sub [mu]][sup SUSY] contribution can have either sign, depending on the sign of the Higgs mixing parameter [mu]: [ital a][sub [mu]][sup SUSY][gt]0 ([lt]0) for [mu][gt]0 ([mu][lt]0). The present [ital a][sub [mu]] constraint excludes chargino masses in the range 45--120 GeV depending on the value of tan[beta], although there are no constraints for tan[beta][approx lt]8. We also compute [ital a][sub [tau]][sup SUSY] and find [vert bar][ital a][sub [tau]][sup SUSY][vert bar][approx]([ital m][sub [tau]]/[ital m][sub [mu]])[sup 2][vert bar][ital a][sub [mu]][sup SUSY][vert bar][approx lt] 10[sup [minus]5] and briefly comment on its possible observability.

• DOE Contract Number: FG05-91ER40633
• OSTI ID: 5340472
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 49:1; ISSN 0556-2821; ISSN PRVDAQ
• Country of Publication: United States
• Language: English

Related Subjects

661310 -- Relativity & Gravitation-- (1992-)
662210* -- Specific Theories & Interaction Models
662390 -- Electromagnetic Processes & Properties-- (1992-)
662430 -- Properties of Leptons-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
LEPTONS
LIE GROUPS
MAGNETIC MOMENTS
MUONS
Pa
Particle Systematics-- Unified Theories & Models-- (1992-)
SU GROUPS
SU-5 GROUPS
SUPERGRAVITY
SUPERSYMMETRY
SYMMETRY
SYMMETRY GROUPS
U GROUPS
U-1 GROUPS
UNIFIED-FIELD THEORIES