181 research outputs found
Bounds for Lepton Flavor Violation and the Pseudoscalar Higgs in the General Two Higgs Doublet Model using muon factor
Current experimental data from the muon factor, seems to show the
necessity of physics beyond the Standard Model (SM), since the difference
between SM and experimental predictions is 2.6. In the framework of
the General Two Higgs Doublet Model (2HDM), we calculate the muon anomalous
magnetic moment to get lower and upper bounds for the Flavour Changing (FC)
Yukawa couplings in the leptonic sector. We also obtain lower bounds for the
mass of the pseudoscalar Higgs () as a function of the parameters of
the model.Comment: 12 pages, RevTex4, 5 figures. Improved presentation, updated
experimental data, amplified analysis, new figures added. Subbmited to Phys.
Rev.
Forecasting the spread of raccoon rabies using a purpose-specific group decisionmaking process
The Centers for Disease Control (CDC) and USDA Wildlife Services (WS) have been involved in an oral rabies vaccination (ORV) program for raccoons (Procyon lotor) that has slowed the westward spread of raccoon rabies. The objective of this study was to forecast the spread of the disease if an ORV zone was not maintained. A group decision-making process was designed to address the forecasting problem and was implemented using a group of 15 experts and 4 support personnel at a meeting at the USDA National Wildlife Research Center. Ten expansion regions were constructed that described the spread of disease at 2-year intervals. This forecast may provide for more accurate cost-benefit analysis of the ORV barrier
Broken R Parity Contributions to Flavor Changing Rates and CP Asymmetries in Fermion Pair Production at Leptonic Colliders
We examine the effects of the R parity odd renormalizable interactions on
flavor changing rates and CP violation asymmetries in the production of
fermion-antifermion pairs at leptonic colliders. The produced
fermions may be leptons, down-quarks or up-quarks, and the center of mass
energies may range from the Z-boson pole up to GeV. Off the Z-boson
pole, the flavor changing rates are controlled by tree level amplitudes and the
CP asymmetries by interference terms between tree and loop level amplitudes. At
the Z-boson pole, both observables involve loop amplitudes. The lepton number
violating interactions, associated with the coupling constants, \l_{ijk},
\l'_{ijk}, are only taken into account. The consideration of loop amplitudes
is restricted to the photon and Z-boson vertex corrections. We briefly review
flavor violation physics at colliders. We present numerical results using a
single, species and family independent, mass parameter, , for all the
scalar superpartners and considering simple assumptions for the family
dependence of the R parity odd coupling constants.Comment: Latex File. 23 pages. 4 postscript figures. 1 table. Revised version
with new results and several corrections in numerical result
Photon-Photon and Electron-Photon Colliders with Energies Below a TeV
We investigate the potential for detecting and studying Higgs bosons in and collisions at future linear colliders with energies below a TeV. Our study incorporates realistic spectra based on available laser technology, and NLC and CLIC acceleration techniques. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson based on a devoted low energy machine with GeV; b) the heavy MSSM Higgs bosons; and c) charged Higgs bosons in collisions.We investigate the potential for detecting and studying Higgs bosons in and collisions at future linear colliders with energies below a TeV. Our study incorporates realistic spectra based on available laser technology, and NLC and CLIC acceleration techniques. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson based on a devoted low energy machine with GeV; b) the heavy MSSM Higgs bosons; and c) charged Higgs bosons in collisions
CP violation in sbottom decays
We study CP asymmetries in two-body decays of bottom squarks into charginos
and tops. These asymmetries probe the SUSY CP phases of the sbottom and the
chargino sector in the Minimal Supersymmetric Standard Model. We identify the
MSSM parameter space where the CP asymmetries are sizeable, and analyze the
feasibility of their observation at the LHC. As a result, potentially
detectable CP asymmetries in sbottom decays are found, which motivates further
detailed experimental studies for probing the SUSY CP phases.Comment: 29 pages, 7 figure
Enhanced contribution to quark and neutron electric dipole moments with small mixing of right-handed currents and CKM CP violation
We study the light quark and the neutron electric dipole moments (EDMs) under
the assumptions that the CP source is still in the usual CKM matrix and that
there is a small mixing of right-handed charged currents in the quark sector.
We find that the EDMs arise already at two loop order that are much larger than
the standard model (SM) result even for a small mixing.Comment: 9 pages, revtex, axodraw.sty, 1 figure, published version in Phys.
Rev. D. References updated, minor corrections and typos fixe
CP Violation, Higgs Couplings, and Supersymmetry
Supersymmetric extensions of the standard model generically contain
additional sources of CP violation. We discuss how at one loop a potentially
large CP violating coupling of the lightest Higgs, h^0, to leptons is induced
in the minimal supersymmetric standard model (MSSM). The CP violating couplings
of h^0 in extensions of the MSSM, such as the next-to-minimal supersymmetric
standard model (NMSSM) are also considered. We indicate how this CP violation
might be observed; in particular a polarization-dependent production asymmetry,
in the context of a muon collider, provides a means to access this coupling
cleanly. In the MSSM, existing limits on the electric dipole moment (EDM) of
the electron, coupled with standard universality assumptions, severly
constrains any such signal. Nevertheless, extensions of the MSSM, such as the
NMSSM, allow CP-violating signals as large as 100%.Comment: 13 pages LaTeX, 4 figures (some typos fixed, discussion clarified
CP asymmetries in the supersymmetric trilepton signal at the LHC
In the CP-violating Minimal Supersymmetric Standard Model, we study the
production of a neutralino-chargino pair at the LHC. For their decays into
three leptons, we analyze CP asymmetries which are sensitive to the CP phases
of the neutralino and chargino sector. We present analytical formulas for the
entire production and decay process, and identify the CP-violating
contributions in the spin correlation terms. This allows us to define the
optimal CP asymmetries. We present a detailed numerical analysis of the cross
sections, branching ratios, and the CP observables. For light neutralinos,
charginos, and squarks, the asymmetries can reach several 10%. We estimate the
discovery potential for the LHC to observe CP violation in the trilepton
channel.Comment: 39 pages, 8 figures, version to appear in EPJC, discussion(s) added,
typo in (D.79), (D.118) corrected, new Fig. 7; The European Physical Journal
C, Volume 72, Issue 3, 201
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