156 research outputs found
Spin Analysis of Supersymmetric Particles
The spin of supersymmetric particles can be determined at colliders
unambiguously. This is demonstrated for a characteristic set of non-colored
supersymmetric particles -- smuons, selectrons, and charginos/neutralinos. The
analysis is based on the threshold behavior of the excitation curves for pair
production in collisions, the angular distribution in the production
process and decay angular distributions. In the first step we present the
observables in the helicity formalism for the supersymmetric particles.
Subsequently we confront the results with corresponding analyses of
Kaluza-Klein particles in theories of universal extra space dimensions which
behave distinctly different from supersymmetric theories. It is shown in the
third step that a set of observables can be designed which signal the spin of
supersymmetric particles unambiguously without any model assumptions. Finally
in the fourth step it is demonstrated that the determination of the spin of
supersymmetric particles can be performed experimentally in practice at an
collider.Comment: 39 pages, 14 figure
Interação de bactérias fluorescentes do gênero Pseudomonas e de Bacillus spp. com a rizosfera de diferentes plantas
Towards Measuring the Stop Mixing Angle at the LHC
We address the question of how to determine the stop mixing angle and its
CP-violating phase at the LHC. As an observable we discuss ratios of branching
ratios for different decay modes of the light stop ~t_1 to charginos and
neutralinos. These observables can have a very strong dependence on the
parameters of the stop sector. We discuss in detail the origin of these
effects. Using various combinations of the ratios of branching ratios we argue
that, depending on the scenario, the observable may be promising in exposing
the light stop mass, the mixing angle and the CP phase. This will, however,
require a good knowledge of the supersymmetric spectrum, which is likely to be
achievable only in combination with results from a linear collider.Comment: 30 pages, 11 figures, version to appear in EPJ
Supersymmetry beyond minimal flavour violation
We review the sources and phenomenology of non-minimal flavour violation in
the MSSM. We discuss in some detail the most important theoretical and
experimental constraints, as well as promising observables to look for
supersymmetric effects at the LHC and in the future. We emphasize the
sensitivity of flavour physics to the mechanism of supersymmetry breaking and
to new degrees of freedom present at fundamental scales, such as the grand
unification scale. We include a discussion of present data that may hint at
departures from the Standard Model.Comment: 23pp. Version to appear in the EPJC special volume "Supersymmetry on
the Eve of the LHC", dedicated to the memory of Julius Wess. References and
brief discussion on collider signatures adde
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TREE COMMUNITY COMPOSITION AND ABOVEGROUND BIOMASS IN A SECONDARY ATLANTIC FOREST, SERRA DO MAR STATE PARK, SÃO PAULO, BRAZIL
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