44,715 research outputs found
Copper and Barium Abundances in the Ursa Major Moving Group
We present Cu and Ba abundances for 7 G-K dwarf stars, members of the
solar-metallicity, 0.3 Gyr old Ursa Major Moving Group. All analyzed member
stars show [Ba/Fe] excesses of +0.3-plus, associated with [Cu/Fe] deficiencies
of up to -0.23 dex. The present results suggest that there is an
anti-correlation between the abundances of Cu and the heavy elements produced
by the main component of the neutron capture s-process. Other possible
anomalies are Na and C deficiencies with respect to normal solar-metallicity
stars. The new data do not confirm the recent claim that the group member
HR6094 is a Ba dwarf star.Comment: 8 pages, 6 figures, accepted to MNRA
Bounds on the Simplest Little Higgs Model Mass Spectrum Through Z Leptonic Decay
We derive the leptonic neutral current in the simplest little Higgs model and
compute the contribution of the model to the decay width . Using
the precision electroweak data we obtain a strong lower bound TeV
at 95% C.L. on the characteristic energy scale of the model. It results in a
lower bound for the new gauge bosons and as being
TeV and TeV, respectively.
We also present the allowed values of the which is the parameter
relating the two vacuum expectation values of the scalar triplets in the model,
and the parameter of a quadratic term, involving the triplets, necessary
to provide an acceptable mass range for the standard Higgs boson.Comment: New references added, 13 pages. Version to be publishe
Real and complex integral closure, Lipschitz equisingularity and applications on square matrices
Recently the authors investigated the Lipschitz triviality of simple germs of
matrices. In this work, we improve some previous results and we present an
extension of an integral closure result for the real setting. These tools are
applied to investigate classes of square matrices singularities classified by
Bruce and Tari
Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation
If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw
mechanism, on the other it is a challenge to find scenarios capable of
realizing it. In this work we propose a scenario, based on the framework of
R-parity violation, that realizes minimally the supersymmetric inverse seesaw
mechanism. In it the energy scale parameters involved in the mechanism are
recognized as the vacuum expectation values of the scalars that compose the
singlet superfields and . We develop also the scalar sector
of the model and show that the Higgs mass receives a new tree-level
contribution that, when combined with the standard contribution plus loop
correction, is capable of attaining GeV without resort to heavy stops.Comment: Minor modification of the text. Final version to be published in PL
Zoneamento agroclimático da cultura do feijoeiro para o Estado de Alagoas.
Neste estudo foi utilizado o modelo SARRA (Sistema de Análise Regional dos Riscos Agroclimáticos).bitstream/CNPAF/25034/1/comt_122.pd
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