4,381 research outputs found
Decay of Z into Three Pseudoscalar Bosons
We consider the decay of the boson into three pseudoscalar bosons in a
general two-Higgs-doublet model. Assuming to be very small, and that of
the two physical neutral scalar bosons and , only couples to
through , we find the branching fraction to be negligible
for moderate values of , if there is no term in the Higgs potential; otherwise there
is no absolute bound but very large quartic couplings (beyond the validity of
perturbation theory) are needed for it to be observable.Comment: 8 pages including 1 fi
Exceeding the MSSM Higgs Mass Bound in a Special Class of U(1) Gauge Models
A special class of supersymmetric U(1) gauge extensions of the standard model
was proposed in 2002. It is anomaly-free, has no mu term, and conserves baryon
and lepton numbers automatically. It also allows the lightest Higgs boson to
have a mass exceeding the MSSM (Minimal Supersymmetric Standard Model) bound,
i.e. about 130 GeV, which is of current topical interest from LHC (Large Hadron
Collider) data. This and other new aspects of this 2002 proposal are discussed.Comment: 10 pages, 2 tables, version to appear in PL
Seeding of Strange Matter with New Physics
At greater than nuclear densities, matter may convert into a mixture of
nucleons, hyperons, dibaryons, and strangelets, thus facilitating the formation
of strange matter even before the onset of the quark-matter phase transition.
From a nonstrange dibaryon condensate, it may even be possible to leapfrog into
strange matter with a certain new interaction, represented by an effective
six-quark operator which is phenomenologically unconstrained.Comment: 7 pages, no figure (Talk given at SQM97
Spontaneous Supersymmetric Generation of an Indeterminate Mass Scale and a Possible Light Sterile Neutrino
If a global continuous symmetry of a supersymmetric field theory is
spontaneously broken while preserving the supersymmetry, the resulting theory
has a massless superfield. One of its two bosonic degrees of freedom is the
familiar phase rotation of the usual massless Nambu-Goldstone boson, but the
other is a scale transformation. An indeterminate mass scale is thus generated.
In the fermion sector, a seesaw texture appears which may be suitable for a
possible light sterile neutrino. This feature persists even after the gauging
of the continuous symmetry or the breaking of the supersymmetry to resolve the
aforementioned mass-scale ambiguity.Comment: 9 pages, expanded to include the discussion of a possible sterile
neutrin
Multiplicative Conservation of Baryon Number and Baryogenesis
In the canonical seesaw mechanism of neutrino mass, lepton number is only
multiplicatively conserved, which enables the important phenomenon of
leptogenesis to occur, as an attractive explanation of the present baryon
asymmetry of the Universe. A parallel possibility, hitherto unrecognized, also
holds for baryon number and baryogenesis. This new idea is shown to be
naturally realized in the context of a known supersymmetric string-inspired
extension of the Standard Model, based on E(6) particle content, and having an
extra U(1)_N gauge symmetry. Within this framework, two-loop radiative neutrino
masses are also possible, together with a new form of very long-lived matter.Comment: 9 pages, 4 figures, 3 table
Revelations of the E_6/U(1)_N Model: Two-Loop Neutrino Mass and Dark Matter
The E_6/U(1)_N gauge extension of the Supersymmetric Standard Model, first
proposed by Ma, is shown to have exactly the requisite ingredients to realize
the important new idea that dark matter is the origin of neutrino mass. With
the implementation of a discrete Z_2 X Z_2 symmetry, and particle content given
by three {27} representations of E_6, neutrino masses are naturally generated
in two loops, with candidates of dark matter in the loops. All particles of
this model are expected to be at or below the TeV scale, allowing them to be
observable at the LHC.Comment: 10 pages, 3 figure
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