Higgs-boson decay to four fermions including a single top quark below [ital t[bar t]] threshold

Journal Article · Sat May 01 00:00:00 EDT 1993 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.47.3886· OSTI ID:6606808

Pois, H ^[1]; Weiler, T J ^[2]; Yuan, T C ^[3]

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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)
2. Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)
3. Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States)

The rare decay modes Higgs boson[r arrow]four light fermions and Higgs boson[r arrow]single top quark+three light fermions for [ital m][sub [ital t]][lt][ital M][sub [ital H]][lt]2[ital m][sub [ital t]] are presented, and phenomenologically interpreted. The angular correlation between fermion planes is presented as a test of the spin and intrinsic parity of the Higgs particle. In Higgs-boson decay to a single top quark, two tree-level graphs contribute in the standard model (SM); one couples the Higgs boson to [ital W][sup +][ital W[minus]] ([similar to][ital gM][sub [ital W]]), and one to [ital t[bar t]] ([similar to][ital g][sub top] Yukawa=[ital m][sub [ital t]]/246 GeV). The large Yukawa coupling for [ital m][sub [ital t]][gt]100 GeV makes the second amplitude competitive or dominant for most [ital M][sub [ital H]], [ital m][sub [ital t]] values. Thus the Higgs-boson decay rate to a single top quark directly probes the SM universal mechanism generating both gauge-boson and fermion masses, and offers a means to infer the Higgs-boson--[ital t[bar t]] Yukawa coupling when [ital H][r arrow][ital t[bar t]] is kinematically disallowed. We find that the modes [ital pp][r arrow][ital Xt[bar t]]([ital H][r arrow][ital t[bar b]W][sup (*)]) at the Superconducting Supe r Collider, and [ital e][sup +][ital e[minus]][r arrow][ital Z] or [nu][bar [nu]]+([ital H][r arrow][ital t[bar b]W][sup (*)]) at future high-energy, high-luminosity colliders, may be measurable if 2[ital m][sub [ital t]] is not too far above [ital M][sub [ital H]]. We classify nonstandard Higgs-bosons as gaugeophobic, fermiophobic, or fermiophilic, and discuss the Higgs boson [r arrow] single top-quark rates for these classes.

• DOE Contract Number: FG05-85ER40226; FG03-84ER40168
• OSTI ID: 6606808
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 47:9; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
HIGGS BOSONS
HADRONIC PARTICLE DECAY
COUPLING CONSTANTS
MASS
PARAMETRIC ANALYSIS
PROTON-PROTON INTERACTIONS
STANDARD MODEL
TOP PARTICLES
BARYON-BARYON INTERACTIONS
DECAY
ELEMENTARY PARTICLES
HADRON-HADRON INTERACTIONS
INTERACTIONS
MATHEMATICAL MODELS
NUCLEON-NUCLEON INTERACTIONS
PARTICLE DECAY
PARTICLE INTERACTIONS
PARTICLE MODELS
POSTULATED PARTICLES
PROTON-NUCLEON INTERACTIONS
UNIFIED GAUGE MODELS
662440* - Properties of Other Particles Including Hypothetical Particles- (1992-)
662340 - Hadron Interactions- (1992-)