54,177 research outputs found
Higher order self-dual models for spin-3 particles in
In dimensions, elementary particles of a given helicity can be
described by local Lagrangians (parity singlets). By means of a "soldering"
procedure two opposite helicities can be joined together and give rise to
massive spin- particles carrying both helicities (parity doublets),
such Lagrangians can also be used in to describe massive spin-
particles. From this point of view the parity singlets (self-dual models) in
are the building blocks of real massive elementary particles in
. In the three cases there are self-dual models
of order in derivatives. In the spin-3 case the 5th order
model is missing in the literature. Here we deduce a 5th order spin-3 self-dual
model and fill up this gap. It is shown to be ghost free by means of a master
action which relates it with the top model of 6th order. We believe that our
approach can be generalized to arbitrary integer spin- in order to obtain
the models of order and . We also comment on the difficulties in
relating the 5th order model with their lower order duals
Natural waters in Amazonia. III. Ammonium molybdate-reactive silica
Natural waters of the Amazonian Tertiary formations along the Manaus-Itacoatjara Road were studied with respect to variations in average seasonal and yearly soluble silica content. In general the variations are small and concentrations very low, for all input fractions, i. e., rainfall, stemflow, and throughfall [about 90 percent of the total (470 analyses) lower than 1.0 mg/l]. While 90 percent of total ground water analyses (excluding well IV 3) have soluble silica concentrations lower than 1.5 mg/l, high rain forest stream waters are slightly higher (90 percent of all values lower than 2.0 mg/l). The Rio Negro waters show 90 percent of the total samples analyzed between 2.0 mg/l and 3.0 mg/l soluble silica
Inert scalar dark matter in an extra dimension inspired model
In this paper we analyze a dark matter model inspired by theories with extra
dimensions. The dark matter candidate corresponds to the first Kaluza-Klein
mode of a real scalar added to the Standard Model. The tower of new particles
enriches the calculation of the relic abundance. For large mass splitting, the
model converges to the predictions of the inert singlet dark matter model. For
nearly degenerate mass spectrum, coannihilations increase the cross-sections
used for direct and indirect dark matter searches. Moreover, the Kaluza-Klein
zero mode can mix with the SM higgs and further constraints can be applied.Comment: 21 pages, 6 figures. We have improved the text and added references.
Version published in JCA
More on dual actions for massive spin-2 particles
Here we start from a dual version of Vasiliev's first order action for
massless spin-2 particles (linearized first order Einstein-Hilbert) and derive,
via Kaluza-Klein dimensional reduction from to dimensions, a set of
dual massive spin-2 models. This set includes the massive "BR" model, a spin-2
analogue of the spin-1 Cremmer-Scherk model. In our approach the linearized
Riemann curvature emerges from a solution of a functional constraint. In
the BR model can be written as a linearized version of a new bimetric
model for massive gravitons. We also have a new massive spin-2 model, in
arbitrary dimensions, invariant under linearized diffeomorphisms. It is given
in terms of a non symmetric rank-2 tensor and a mixed symmetry tensor.Comment: 18 pages, 0 figure
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