8,280 research outputs found
Will at least one of the Higgs bosons of the next-to-minimal supersymmetric extension of the Standard Model be observable at LEP2 or the LHC?
We demonstrate that there are regions of parameter space in the
next-to-minimal (i.e. two-Higgs-doublet, one-Higgs-singlet superfield)
supersymmetric extension of the SM for which none of the Higgs bosons are
observable either at LEP2 with and an integrated luminosity
of or at the LHC with .Comment: 6 pages, full postscript file also available via anonymous ftp at
ftp://ucdhep.ucdavis.edu/gunion/nmssm_sm96.ps To appear in ``Proceedings of
the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics'
Charginos and Neutralinos Production at 3-3-1 Supersymmetric Model in Scattering
The goal of this article is to derive the Feynman rules involving charginos,
neutralinos, double charged gauge bosons and sleptons in a 3-3-1 supersymmetric
model. Using these Feynman rules we will calculate the production of a double
charged chargino with a neutralino and also the production of a pair of single
charged charginos, both in an electron- electron process.Comment: 18 pages, 8 figures, 2 table
Mass-degenerate Higgs bosons at 125 GeV in the Two-Higgs-Doublet Model
The analysis of the Higgs boson data by the ATLAS and CMS Collaborations
appears to exhibit an excess of h --> gamma\gamma events above the Standard
Model (SM) expectations; whereas no significant excess is observed in h --> ZZ*
--> {four lepton} events, albeit with large statistical uncertainty due to the
small data sample. These results (assuming they persist with further data)
could be explained by a pair of nearly mass-degenerate scalars, one of which is
a SM-like Higgs boson and the other is a scalar with suppressed couplings to
W+W- and ZZ. In the two Higgs doublet model, the observed \gamma\gamma and ZZ*
--> {four lepton} data can be reproduced by an approximately degenerate CP-even
(h) and CP-odd (A) Higgs boson for values of \sin(\beta-\alpha) near unity and
0.7 < \tan\beta < 1. An enhanced \gamma\gamma signal can also arise in cases
where m_h ~ m_H, m_H ~ m_A, or m_h ~ m_H ~ m_A. Since the ZZ* --> {four lepton}
signal derives primarily from a SM-like Higgs boson whereas the \gamma\gamma
signal receives contributions from two (or more) nearly mass-degenerate states,
one would expect a slightly different invariant mass peak in the ZZ* --> {four
lepton} and \gamma\gamma channels. The phenomenological consequences of such
models can be tested with additional Higgs data that will be collected at the
LHC in the near future.Comment: 18 pages, 19 pdf figures, v2: references added, v3&v4: added refs and
explanation
Derivation of and in the Minimal Supersymmetric Standard Model
In the minimal supersymmetric standard model, the Higgs sector has two
unknown parameters, usually taken to be and ,
the mass of its one physical pseudoscalar particle. By minimizing the minimum
of the Higgs potential along a certain direction in parameter space, it is
shown that + radiative correction, and if one further plausible
assumption is made, .Comment: 7 pages, University of California, Riverside Report No. UCRHEP-T105
(Feb 1993). [Discussion of radiative correction is now included.
Detection of Minimal Supersymmetric Model Higgs Bosons in \gam\gam Collisions: Influence of SUSY Decay Modes
We demonstrate that supersymmetric decay modes of the neutral Higgs bosons of
the MSSM could well make their detection extremely difficult when produced
singly in \gam\gam collisions at a back-scattered laser beam facility.Comment: 12 pages, requires phyzzx.tex and tables.tex, full postscript file
including embedded tables available via anonymous ftp at ucdhep.ucdavis.edu
as [anonymous.gunion]gamgamsusy.ps, preprint UCD-94-3
Strategies to link tiny neutrino masses with huge missing mass of the Universe
With the start of the LHC, interest in electroweak scale models for the
neutrino mass has grown. In this letter, we review two specific models that
simultaneously explain neutrino masses and provide a suitable DM candidate. We
discuss the implications of these models for various observations and
experiments including the LHC, Lepton Flavor Violating (LFV) rare decays,
direct and indirect dark matter searches and Kaon decay.Comment: 17 pages, one diagram, talk given at International Conference on
Flavor Physics in the LHC era in Singapor
Production of neutral scalar Higgs bosons at colliders
We study the production of neutral scalar (CP even) Higgs bosons in the
process by including supersymmetric corrections to the
dominant -channel photon exchange amplitude. In addition to the standard
model and fermion loops, there are substantial contributions from
chargino loops. For some cases, these contributions can exceed those of the
's and ordinary fermions. The cross sections in this channel are generally
one or two orders of magnitude larger than those in the related channel
.Comment: 12 pages RevTeX, 5 postscript figures included, uses epsf.st
Space shuttle electromagnetic environment experiment. Phase A: Definition study
A program is discussed which develops a concept for measuring the electromagnetic environment on earth with equipment on board an orbiting space shuttle. Earlier work on spaceborne measuring experiments is reviewed, and emissions to be expected are estimated using, in part, previously gathered data. General relations among system parameters are presented, followed by a proposal on spatial and frequency scanning concepts. The methods proposed include a nadir looking measurement with small lateral scan and a circularly scanned measurement looking tangent to the earth's surface at the horizon. Antenna requirements are given, assuming frequency coverage from 400 MHz to 40 GHz. For the low frequency range, 400-1000 MHz, a processed, thinned array is proposed which will be more fully analyzed in the next phase of the program. Preliminary hardware and data processing requirements are presented
Radiative Corrections to the Vertex and Constraints on Extended Higgs Sectors
We explore the radiative corrections to the process in
models with extended Higgs sectors. The observables and the coupling asymmetry, , are sensitive to these corrections. We
present general formulae for the one-loop corrections to and in an
arbitrary extended Higgs sector, and derive explicit results for a number of
specific models. We find that in models containing only doublets, singlets, or
larger multiplets constrained by a custodial symmetry so that at tree level, the one-loop corrections due to virtual
charged Higgs bosons always worsen agreement with experiment. The
measurement can be used to set lower bounds on the charged Higgs masses.
Constraints on models due to the one-loop contributions of neutral Higgs bosons
are also examined.Comment: 54 pages, 11 figure
Effects of Bose-Einstein Condensation on forces among bodies sitting in a boson heat bath
We explore the consequences of Bose-Einstein condensation on
two-scalar-exchange mediated forces among bodies that sit in a boson gas. We
find that below the condensation temperature the range of the forces becomes
infinite while it is finite at temperatures above condensation.Comment: 10 pages, 2 figure
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