92 research outputs found
Non-minimal neutral Higgs bosons at LEP2
We study the phenomenology of the neutral Higgs sector of a non-SUSY
non-minimal Standard Model. Models with more than one Higgs doublet are
possible, and may contain neutral Higgs scalars with branching ratios
significantly different to those of the Minimal Standard Model Higgs boson. We
show how these differences may be exploited at LEP2 in order to distinguish the
non-minimal Standard Model from the minimal version.Comment: 12 pages inc 4 figures, Latex, to appear in Physics Letters
Searching for a light Fermiophobic Higgs Boson at the Tevatron
We propose new production mechanisms for light fermiophobic Higgs bosons
() with suppressed couplings to vector bosons () at the Fermilab
Tevatron. These mechanisms (e.g. ) are complementary to the
conventional process , which suffers from a strong suppression of
in realistic models with a . The new mechanisms extend the
coverage at the Tevatron Run II to the larger region, and offer the
possibility of observing new event topologies with up to 4 photons.Comment: 15 pages, including 5 eps-figure
Charged Higgs bosons in the Next-to MSSM (NMSSM)
The charged Higgs boson decays and
are studied in the framework of the next-to Minimal Supersymmetric Standard
Model (NMSSM). It is found that the decay rate for can
exceed the rates for the and channels both below and above
the top-bottom threshold. The dominance of is most readily
achieved when has a large doublet component and small mass. We also study
the production process at the LHC followed by the decay
which leads to the signature . We suggest
that is a promising discovery channel for a light charged
Higgs boson in the NMSSM with small or moderate and dominant decay
mode . This signature can also arise from
the Higgsstrahlung process followed by the decay . It is shown that there exist regions of parameter space where these
processes can have comparable cross sections and we suggest that their
respective signals can be distinguished at the LHC by using appropriate
reconstruction methods.Comment: 20 pages, 22 eps figures, more reference adde
Fermiophobic Higgs bosons at the Tevatron
Higgs bosons with negligible couplings to fermions can arise in various
non--minimal Higgs sectors. We show that such a particle could be discovered
during the current run at the Tevatron, and would be evidence against a minimal
supersymmetric Higgs sector.Comment: 10 pages, Latex, 5 figures, to appear in Phys. Lett. B, figures
include
Charged Higgs boson contribution to scattering from low to ultrahigh energy in Higgs triplet model
We study the scattering from low to ultrahigh energy in the
framework of Higgs Triplet Model (HTM). We add the contribution of charged
Higgs boson exchange to the total cross section of the scattering. We obtain
the upper bound in this
process from low energy experiment. We show that by using the upper bound
obtained, the charged Higgs contribution can give enhancements to the total
cross section with respect to the SM prediction up to 5.16% at
eV and maximum at and would help to determine the
feasibility experiments to discriminate between SM and HTM at current available
facilities.Comment: 6 pages, 6 figure
Tau Lepton Mixing with Charginos and its Effects on Chargino Searches at e+e- Colliders
In bilinear R-Parity violating models where a term \epsilon_3L_3H_2 is
introduced in the superpotential, the tau lepton can mix with charginos. We
show that this mixing is fully compatible with LEP1 precision measurements of
the Z\tau\tau and W\tau\nu_\tau couplings even for large values of \epsilon_3
and of the induced vacuum expectation value v_3 of the tau-sneutrino. The
single production of charginos at e+e- colliders is possible in this case and
we present numerical values of the cross-section at LEP1, LEP2 and an NLC. We
find maximum values of 10 pb at LEP1 and 1 fb at NLC, while the corresponding
values at LEP2 are too small to observe.Comment: 16 pages (including 7 figures), LaTex, uses axodraw.sty (included
Large mass splittings between charged and neutral Higgs bosons in the MSSM
We show that large ( GeV) mass splittings between the charged Higgs
boson () and the neutral Higgs bosons ( and ) are possible in
the Minimal Supersymmetric Standard Model (MSSM). Such splittings occur when
the parameter is considerably larger than the common SUSY scale,
, and have significant consequences for MSSM Higgs searches at future
colliders.Comment: 11 pages, LaTex, 5 figures, version to appear in Phys. Lett.
Cascade decays of triplet Higgs bosons at LEP2
We study the Georgi-Machacek two triplet, one doublet model in the context of
LEP2, and show that cascade decays of Higgs bosons to lighter Higgs bosons and
a virtual vector boson may play a major role. Such decays would allow the Higgs
bosons of this model to escape current searches, and in particular are of great
importance for the members of the five-plet which will always decay to the
three-plet giving rise to cascade signatures.Comment: 17 pages Latex, 6 figures, some graphs changed slightly, a formula
corrected, to appear in Physics Letters
Three-body decays of Higgs bosons at LEP2 and application to a hidden fermiophobic Higgs
We study the decays of Higgs bosons to a lighter Higgs boson and a virtual
gauge boson in the context of the non-supersymmetric Two-Higgs-Doublet-Model
(2HDM). We consider the phenomenological impact at LEP2 and find that such
decays, when open, may be dominant in regions of parameter space and thus
affect current Higgs boson search techniques. Three-body decays would be a way
of producing light neutral Higgs bosons which have so far escaped detection at
LEP due to suppressed couplings to the , and are of particular importance in
the 2HDM (Model I) which allows both a light fermiophobic Higgs and a light
charged scalar.Comment: 23 pages Latex, 9 figures, references added, alterations to text in
sections 3 and 5, some graphs changed slightly, to appear in Nuclear Physics
Associated production of H^{\pm} and W^{\mp} in high-energy e+e- collisions in the Minimal Supersymmetric Standard Model
We study the associated production of the charged Higgs boson and W^{\pm}
gauge boson in high energy e+e- collisions in the Minimal Supersymmetric
Standard Model (MSSM). This associated production, which first arises at the
one loop level, offers the possibility of producing the charged Higgs boson at
the e+e- collider with mass more than half the center-of-mass energy, when the
charged Higgs pair production is kinematically forbidden. We present analytic
and numerical results for the cross section for e+e- --> W+ H- in the full
MSSM, taking into account the previously uncalculated contributions from
supersymmetric (SUSY) particles. We find that the contributions of the SUSY
particles enhance the cross section over most of SUSY parameter space,
especially when the SUSY particles are light, ~200 GeV. With favorable SUSY
parameters, at small tan beta, this process can yield more than ten
W^{\pm}H^{\mp} events for m_{H^{\pm}} <~ 350 GeV in 500 fb-1 at a 500 GeV e+e-
collider, or m_{H^{\pm}} <~ 600 GeV in 1000 fb-1 at a 1000 GeV collider. 80%
left-handed polarization of the e- beam improves these reaches to m_{H^{\pm}}
<~ 375 GeV and m_{H^{\pm}} <~ 670 GeV, respectively.Comment: v2: 21 pages, 9 figures, comments on Higgs search bounds and new
references added, and minor changes; v3: 23 pages, 11 figures, review of
literature moved from introduction to new Sec.5 and 2 plots added, references
added, typos corrected; v4: bug fixed in nu nubar H0 cross section (Fig.11),
version to appear in PR
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