1,091 research outputs found
Speculations on Isolated Lepton Events at HERA
Speculations on mechanisms which might be responsible for events with an
isolated high p_T lepton, a hadron jet and missing energy, as observed in the
H1 experiment at HERA, are discussed.Comment: LaTeX, 6 pages, 2 figures, presented at the XXXI Conference of
Theoretical Physics "Matter to the Deepest", Ustron, Poland, September 5-11,
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Reconstructing Supersymmetry at ILC/LHC
Coherent analyses of experimental results from LHC and ILC will allow us to
draw a comprehensive and precise picture of the supersymmetric particle sector.
Based on this platform the fundamental supersymmetric theory can be
reconstructed at the high scale which is potentially close to the Planck scale.
This procedure will be reviewed for three characteristic examples: minimal
supergravity as the paradigm; a left-right symmetric extension incorporating
intermediate mass scales; and a specific realization of string effective
theories.Comment: published in Proceedings of the Ustron Conference 2005; technical
LaTeX problem correcte
Neutralino relic density from ILC measurements in the CPV MSSM
We discuss ILC measurements for a specific MSSM scenario with CP phases,
where the lightest neutralino is a good candidate for dark matter, annihilating
efficiently through t-channel exchange of light staus. These prospective
(CP-even) ILC measurements are then used to fit the underlying model
parameters. A collider prediction of the relic density of the neutralino from
this fit gives 0.116<Omega h^2<0.19 at 95% CL. CP-odd observables, while being
a direct signal of CP violation, do not help in further constraining Omega h^2.
The interplay with (in)direct detection of dark matter and with measurements of
electric dipole moments is also discussed. Finally we comment on collider
measurements at higher energies for refining the prediction of Omega h^2.Comment: 24 pages, 13 figure
Reconstruction of Fundamental SUSY Parameters
We summarize methods and expected accuracies in determining the basic
low-energy SUSY parameters from experiments at future ee linear
colliders in the TeV energy range, combined with results from LHC. In a second
step we demonstrate how, based on this set of parameters, the fundamental
supersymmetric theory can be reconstructed at high scales near the grand
unification or Planck scale. These analyses have been carried out for minimal
supergravity [confronted with GMSB for comparison], and for a string effective
theory.Comment: 8 pages, latex, 7 figures, expanded version of contributions to the
proceedings of ICHEP.2002 (Amstersdam) and LCWS.2002 (Jeju Island
Gamma-Ray Constraint on Galactic Positron Production by MeV Dark Matter
The Galactic positrons, as observed by their annihilation gamma-ray line at
0.511 MeV, are difficult to account for with astrophysical sources. It has been
proposed that they are produced instead by dark matter annihilation or decay in
the inner Galactic halo. To avoid other constraints, these processes are
required to occur "invisibly," such that the eventual positron annihilation is
the only detectable signal. However, electromagnetic radiative corrections to
these processes inevitably produce real gamma rays (``internal
bremsstrahlung"); this emission violates COMPTEL and EGRET constraints unless
the dark matter mass is less than about 20 MeV.Comment: 4 pages, 2 figures, submitted to Physical Review Letter
SUSY Parameter Analysis at TeV and Planck Scales
Coherent analyses at future LHC and LC experiments can be used to explore the
breaking mechanism of supersymmetry and to reconstruct the fundamental theory
at high energies, in particular at the grand unification scale. This will be
exemplified for minimal supergravity.Comment: 7 pages, 3 figures, uses espcrc2.sty (included), Proceedings, Loops
and Legs 2004, Zinnowitz on Usedo
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