240 research outputs found
Measuring the Supersymmetry Lagrangian
The parameters of the supersymmetry Lagrangian are the place where experiment
and theory will meet. We show that measuring them is harder than has been
thought, particularly because of large unavoidable dependences on phases.
Measurements are only guaranteed if a lepton collider with a polarized beam and
sufficient energy to produce the relevant sparticles is available. Current
limits on superpartner masses, WIMPs, and the supersymmetric Higgs are not
general, and need re-evaluation. We also tentatively define the MRM (Minimum
Reasonable Model), whose parameters may be measurable at LEP, FNAL and LHC.Comment: 10 pages, 1 figure; a typographical error corrected in eq. (1) and
one reference adde
Weighing the universe with accelerators and detectors
Suppose the lightest superpartner (LSP) is observed at colliders, and WIMPs
are detected in explicit experiments. We point out that one cannot immediately
conclude that cold dark matter (CDM) of the universe has been observed, and we
determine what measurements are necessary before such a conclusion is
meaningful. We discuss the analogous situation for neutrinos and axions; in the
axion case we have not found a way to conclude axions are the CDM even if
axions are detected.Comment: 15 pages, 3 figures; minor changes included and typos fixe
CP Violation beyond the Standard Model
In this talk a number of broad issues are raised about the origins of CP
violation and how to test the ideas.Comment: 17 pages, LaTeX, 6 postscript figures. Uses iopart10.clo,
iopart12.clo and iopart.cls. Plenary talk given at the BSM Phenomenology
Workshop, Durham, UK, 6-11 May 2001. To appear in the proceeding
Determining the Actual Local Density of Dark Matter Particles
Even if dark matter particles are unambiguously discovered in experiments,
there is no clear reason to expect that the dark matter problem has been
solved. It is very easy to provide examples of dark matter scenarios (e.g. in
supersymmetric models) where nearly identical detector signals correspond to
extremely different relic densities. Therefore, the density of the particles
discovered must be determined before their cosmological relevance is
established. In this talk, I will present a general method to estimate the
local density of dark matter particles using both dark matter and hadron
collider experimental data when it becomes available. These results were
obtained in collaboration with Gordon Kane at the University of Michigan.Comment: 9 pages, 4 figures. Talk given at the 42nd International School of
Subnuclear Physics at Erice, Sicily, 30 August 200
Gaugino CP phases and EDMs in the extended gauge mediation SUSY breaking
We study phenomenological aspects of the soft supersymmetry breaking
parameters in a model with the extended gauge mediation supersymmetry breaking.
In this model gaugino masses can be non-universal and as its result physical
CP-phases remain in the gaugino sector even after the R-transformation. These
phases contribute to the electric dipole moment (EDM) of an electron and a
neutron. We show that their experimental bounds can be satisfied even for the
situation such that there exist the order one CP-phases and the masses of
superpartners are of the order of 100 GeV.Comment: LaTeX, 26 pages, 6 figure
Flavour-Dependent CP Violation and Natural Suppression of the Electric Dipole Moments
We revisit the supersymmetric CP problem and find that it can be naturally
resolved if the origin of CP violation is closely related to the origin of
flavour structures. In this case, the supersymmetry breaking dynamics do not
bring in any new CP-violating phases. This mechanism requires hermitian Yukawa
matrices which naturally arise in models with a U(3) flavour symmetry. The
neutron electric dipole moment (NEDM) is predicted to be within one-two orders
of magnitude below the current experimental limit. The model also predicts a
strong correlation between A_{CP}(b --> s gamma)and the NEDM. The strong CP
problem is mitigated although not completely solved.Comment: revtex, 4 page
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