1,177 research outputs found
Searching for Doubly-Charged Higgs Bosons at Future Colliders
Doubly-charged Higgs bosons () appear in several
extensions to the Standard Model and can be relatively light. We review the
theoretical motivation for these states and present a study of the discovery
reach in future runs of the Fermilab Tevatron for pair-produced doubly-charged
Higgs bosons decaying to like-sign lepton pairs. We also comment on the
discovery potential at other future colliders.Comment: 6 pages, full postscript file also available via anonymous ftp at
ftp://ucdhep.ucdavis.edu/gunion/hmm_sm96.ps To appear in ``Proceedings of the
1996 DPF/DPB Summer Study on New Directions for High Energy Physics'
Full O(alpha) corrections to e+e- -> sf_i sf_j
We present a complete precision analysis of the sfermion pair production
process e+e- -> sf_i sf_j (f = t, b, tau, nu_tau) in the Minimal Supersymmetric
Standard Model. Our results extend the previously calculated weak corrections
by including all one-loop corrections together with higher order QED
corrections. We present the details of the analytical calculation and discuss
the renormalization scheme. The numerical analysis shows the results for total
cross-sections, forward-backward and left-right asymmetries. It is based on the
SPS1a' point from the SPA project. The complete corrections are about 10% and
have to be taken into account in a high precision analysis.Comment: 32 pages, 24 figures, RevTeX
A No-Lose Theorem for Higgs Searches at a Future Linear Collider
Assuming perturbativity up to a high energy scale GeV, we
demonstrate that a future linear collider operating at
500 GeV with 500 fb per year (such as the recently
proposed TESLA facility) will detect a Higgs boson signal regardless of the
complexity of the Higgs sector and of how the Higgs bosons decay.Comment: 4 pages, LaTe
The Precision of Higgs Boson Measurements and Their Implications
The prospects for a precise exploration of the properties of a single or many
observed Higgs bosons at future accelerators are summarized, with particular
emphasis on the abilities of a Linear Collider (LC). Some implications of these
measurements for discerning new physics beyond the Standard Model (SM) are also
discussed.Comment: Summary report of the Precision Higgs Working Group P1WG2 at Snowmass
200
Explicit CP violation in a MSSM with an extra
We study that a minimal supersymmetric standard model with an extra
gauge symmetry may accommodate the explicit CP violation at the one-loop level
through radiative corrections. This model is CP conserving at the tree level
and cannot realize the spontaneous CP violation for a wide parameter space at
the one-loop level. In explicit CP violation scenario, we calculate the Higgs
boson masses and the magnitude of the scalar-pseudoscalar mixings in this model
at the one-loop level by taking into account the contributions of top quarks,
bottom quarks, exotic quarks, and their superpartners. In particular, we
investigate how the exotic quarks and squarks would affect the
scalar-pseudoscalar mixings. It is observed that the size of the mixing between
the heaviest scalar and pseudoscalar Higgs bosons is changed up to 20 % by a
complex phase originated from the exotic quark sector of this model.Comment: 19 pages, 3 figure
Unusual Charged Higgs Signals at LEP-2
We have made a detailed study of the signals produced at LEP-2 from charged
scalar bosons whose dominant decay channels are into four fermions. The event
rates as well as kinematics of the final states are discussed when such scalars
are either pair-produced or are generated through a tree-level interaction
involving a charged scalar, the W and the Z. The backgrounds in both cases are
discussed. We also suggest the possibility of reconstructing the mass of such a
scalar at LEP-2.Comment: 12 pages, LateX, 9 Postscript figures, uses eps
Higgs bosons of a supersymmetric model at the ILC
We study the scalar Higgs sector of the next-to-minimal supersymmetric
standard model with an extra U(1), which has two Higgs doublets and a Higgs
singlet, in the light leptophobic scenario where the extra neutral gauge
boson does not couple to charged leptons. In this model, we find that the
sum of the squared coupling coefficients of the three neutral scalar Higgs
bosons to , normalized by the corresponding SM coupling coefficient is
noticeably smaller than unity, due to the effect of the extra U(1), for a
reasonable parameter space of the model, whereas it is unity in the
next-to-minimal supersymmetric standard model. Thus, these two models may be
distinguished if the coupling coefficients of neutral scalar Higgs bosons to
are measured at the future International Linear Collider by producing them
via the Higgs-strahlung, fusion, and fusion processes.Comment: 12 pages, 2 figures, 1 table, PR
Conditions for CP-Violation in the General Two-Higgs-Doublet Model
The most general Higgs potential of the two-Higgs-doublet model (2HDM)
contains three squared-mass parameters and seven quartic self-coupling
parameters. Among these, one squared-mass parameter and three quartic coupling
parameters are potentially complex. The Higgs potential explicitly violates CP
symmetry if and only if no choice of basis exists in the two-dimensional Higgs
``flavor'' space in which all the Higgs potential parameters are real. We
exhibit four independent potentially complex invariant (basis-independent)
combinations of mass and coupling parameters and show that the reality of all
four invariants provides the necessary and sufficient conditions for an
explicitly CP-conserving 2HDM scalar potential. Additional potentially complex
invariants can be constructed that depend on the Higgs field vacuum expectation
values (vevs). We demonstrate how these can be used together with the
vev-independent invariants to distinguish between explicit and spontaneous
CP-violation in the Higgs sector.Comment: 46 pages, minor typographical errors corrected, accepted for
publication in Phys. Rev.
Radiative corrections to the Higgs boson decay rate in the minimal supersymmetric model
We consider radiative corrections to the decay rate
of the heavy {\it CP}-even Higgs boson of the minimal supersymmetric model to
two bosons. We perform a one loop Feynman diagram calculation in the
on-mass-shell renormalization scheme, and include the third generation of
quarks and squarks. The tree level rate is suppressed by a mixing angle factor
and decreases as for large . The corrected rate overcomes this
suppression and increases with for ~GeV. The corrections can
be very large and depend in detail on the top squark masses and -term, as
well as the supersymmetric Higgs mass parameter .Comment: 22 pages, 9 figures available from authors, UCB-PTH-92/23 and
LBL-3249
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