1 research outputs found
Higgs-Boson Decay to Four Fermions Including a Single Top Quark Below Threshold
The rare decay modes Higgs four light fermions, and Higgs
single top-quark + three light fermions for , 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 decay to single top, two tree-level graphs contribute
in the standard model (SM); one couples the Higgs to , and
one to t\bar t(\sim g_{top\;yukawa}=m_t/246\GeV). The large Yukawa coupling
for m_t>100\GeV makes the second amplitude competitive or dominant for most
values. Thus the Higgs decay rate to single top directly probes the
SM universal mechanism generating both gauge boson and fermion masses, and
offers a means to infer the Higgs- Yukawa coupling when is kinematically disallowed. We find that the modes at the SSC, and at future high energy,
high luminosity colliders, may be measureable if is not too far above
. We classify non-standard Higgses as gaugeo-phobic, fermio-phobic or
fermio-philic, and discuss the Higgs single top rates for these
classes.Comment: 30 pages, 6 figures (figures available upon request); VAND-TH-93/