Phenomenological consequences of an enhanced top-quark Yukawa coupling

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.31.95· OSTI ID:6247670

Sher, M; Silverman, D

In models with more than one Higgs doublet, the Yukawa couplings of the d-type (u-type) quarks are changed by a factor A/sub d/ (A/sub u/), which is often a ratio of vacuum expectation values. Abbott, Sikivie, and Wise showed that the K/sub L/-K/sub S/ mass difference places stringent constraints on A/sub u/ (A/sub u/< or approx. =10 for a charged-Higgs-boson mass of m/sub W/); however, this bound is very sensitive to the charged-Higgs-boson mass and to small Kobayashi-Maskawa mixing angles. We note that if the enhancement is greater than 4--5, then the top quark's Yukawa coupling will exceed its strong coupling, even if m/sub t/approx.35 GeV. The effects of this enhancement on the e/sup +/e/sup -/ cross section, on energy levels, leptonic widths, and decay rate of t-quarkonium, and on top-quark decays are discussed; the former two effects are sensitive to neutral-scalar masses only, the latter to the charged-Higgs-boson mass; all of the effects are insensitive to small mixing angles. We also note that the best limit on A/sub d/ comes from recent data on the semileptonic branching ratio of b quarks.

• Research Organization: Department of Physics, University of California, Irvine, Irvine, California 92717
• OSTI ID: 6247670
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 31:1; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645203* -- High Energy Physics-- Particle Interactions &amp; Properties-Theoretical-- Weak Interactions &amp; Properties
645400 -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
BASIC INTERACTIONS
BOSONS
BRANCHING RATIO
CROSS SECTIONS
DECAY
ELECTROMAGNETIC INTERACTIONS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
FIELD THEORIES
HADRONS
HIGGS BOSONS
INTERACTIONS
KAONS
LEPTON-LEPTON INTERACTIONS
MASS DIFFERENCE
MATHEMATICAL MODELS
MESONS
PARTICLE DECAY
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
POSTULATED PARTICLES
PSEUDOSCALAR MESONS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARKONIUM
QUARKS
SEMILEPTONIC DECAY
STRANGE PARTICLES
STRONG-COUPLING MODEL
WEAK PARTICLE DECAY