23,163 research outputs found
Interplay between Hbs and bsgamma in the MSSM with Non-Minimal Flavour Violation
We investigate the constraints on flavour-changing neutral heavy Higgs-boson
decays H-> b \bar s from b -> s gamma bounds on the flavour-mixing parameters
of the MSSM with non-minimal flavour violation (NMFV). In our analysis we
include the contributions from the SM and new physics due to general flavour
mixing in the squark mass matrices. We study the case of one and two non-zero
flavour-mixing parameters and find that in the latter case the interference can
raise the Higgs flavour-changing branching ratios by one or two orders of
magnitude with respect to previous predictions based on a single non-zero
parameter and in agreement with present constraints from physics. In the
course of our work we developed a new "FeynArts" model file for the NMFV MSSM
and added the necessary code for the evaluation to "FormCalc". Both extensions
are publicly available.Comment: LaTeX2e, 15 pages, 4 figures. Computation improved and figures
replaced accordingly. Some references added. Main conclusions remain
untouche
Higher-Order Corrected Higgs Bosons in FeynHiggs 2.5
Large higher-order corrections enter the Higgs boson sector of the MSSM via
Higgs-boson self-energies. Their effects have to be taken into account for the
correct treatment of loop-corrected Higgs-boson mass eigenstates as external
(on-shell) or internal particles in Feynman diagrams. We review how the loop
corrections, including momentum dependence and imaginary contributions, are
correctly taken into account for external (on-shell) Higgs boson and how
effective couplings can be derived. The proceedures are implemented in the code
FeynHiggs 2.5.Comment: 8 pages, no figures. Two talks given at the LCWS06 March 2006,
Bangalore, Indi
Two-loop SUSY QCD corrections to the chargino masses in the MSSM
We have calculated the two-loop strong interaction corrections to the
chargino pole masses in the DRbar'-scheme in the Minimal Supersymmetric
Standard Model (MSSM) with complex parameters. We have performed a detailed
numerical analysis for a particular point in the parameter space and found
corrections of a few tenths of a percent. We provide a computer program which
calculates chargino and neutralino masses with complex parameters including the
one-loop corrections and all two-loop SQCD effects.Comment: 12 pages, 11 figures, references modified, clarifications adde
Magnetic properties of -FeCr alloy as calculated with the charge and spin self-consistent KKR(CPA) method
Magnetic properties of a FeCr alloy calculated with
the charge and spin self- consistent Korringa-Kohn-Rostoker (KKR) and combined
with coherent potential approximation (KKR-CPA) methods are reported.
Non-magnetic state as well as various magnetic orderings were considered, i.e.
ferromagnetic (FM) and more complex anti-parallel (called APM) arrangements for
selected sublattices, as follows from the symmetry analysis. It has been shown
that the Stoner criterion applied to non-magnetic density of states at the
Fermi energy, is satisfied for Fe atoms situated on all five lattice
sites, while it is not fulfilled for all Cr atoms. In FM and APM states, the
values of magnetic moments on Fe atoms occupying various sites are dispersed
between 0 and 2.5 , and they are proportional to the number of Fe atoms
in the nearest-neighbor shell. Magnetic moments of Cr atoms havin much smaller
values were found to be coupled antiparallel to those of Fe atoms. The average
value of the magnetic moment per atom was found to be that
is by a factor of 4 larger than the experimental value found for a
FeCr sample. Conversely, admitting an anti-
parallel ordering (APM model) on atoms situated on C and D sites, according to
the group theory and symmetry analysis results, yielded a substantial reduction
of to 0.20 $\mu_B$. Further diminution of to 0.15 ,
which is very close to the experimental value of 0.14 , has been
achieved with the KKR-CPA calculations by considering a chemical disorder on
sites B, C and D
CP violating asymmetry in decays
The CP violating asymmetry from the decay rates of
charged Higgs bosons into the lightest neutral Higgs boson and a boson
is calculated and discussed in the complex MSSM. The contributions from all
complex phases are considered, especially from the top-squark trilinear
coupling, which induces a large contribution to the CP asymmetry.Comment: 19 pages, 10 figures, version published in JHE
Hadronic production of bottom-squark pairs with electroweak contributions
We present the complete computation of the tree-level and the next-to-leading
order electroweak contributions to bottom-squark pair production at the LHC.
The computation is performed within the minimal supersymmetric extension of the
Standard Model. We discuss the numerical impact of these contributions in
several supersymmetric scenarios.Comment: 33 pages, v2: preprint numbers correcte
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