12,419 research outputs found
An analysis of the Lattice QCD spectra for and
In this talk I present the results obtained using effective field theories in
a finite volume from a reanalysis of lattice data on the systems,
where bound states of and are found and associated with the states
and , respectively. We confirm the presence of
such states on the lattice data and determine the weight of the channel in
the wave function of and that of in the wave function
of . Our results indicate a large meson-meson component in both
cases.Comment: Conference Proceedings, Hadron 2017, Salamanca, Spai
Higher Dimensional Classical W-Algebras
Classical -algebras in higher dimensions are constructed. This is achieved
by generalizing the classical Gel'fand-Dickey brackets to the commutative limit
of the ring of classical pseudodifferential operators in arbitrary dimension.
These -algebras are the Poisson structures associated with a higher
dimensional version of the Khokhlov-Zabolotskaya hierarchy (dispersionless
KP-hierarchy). The two dimensional case is worked out explicitly and it is
shown that the role of Diff is taken by the algebra of generators of
local diffeomorphisms in two dimensions.Comment: 22 pages, Plain TeX, KUL-TF-92/19, US-FT/6-9
Movimentação de inseticidas de tratamento de sementes no solo sob efeito da irrigação.
Este trabalho foi desenvolvido no Centro Nacional de Pesquisa de Milho e Sorgo (CNPMS), EMBRAPA, Sete Lagoas, MG, e teve como objetivo avaliar o movimento de inseticidas de tratamento de sementes de milho no perfil do solo em areas irrigadas. Foram utilizadas tres laminas de irrigacao: deficiente (50% da adequada), adequada e excessiva (100% superior a adequada), e dois inseticidas de tratamento de semente de milho: Semevin 350 RA (Thiodicarb) e Furadan 350 TS (Carbofuran), nas doses recomendadas pelos fabricantes. O monitoramento da lixiviacao desses inseticidas no solo foi feito em camadas de 5 cm e em quatro intervalos de 10 dias, a partir semeadura. A analise de residuo das amostras de solo foi feita utilizando-se cromatografia liquida de alta performance (HPLC). Nas condicoes em que foi realizado o experimento obtiveram-se as seguintes conclusoes: o Thiodicarb apresentou-se o mais instavel (com relacao a sua atividade) no solo com baixo risco de contaminacao do lencol freatico; o Carbofuran apresentou-se com um potencial maior de lixiviacao no perfil do solo devido, possivelmente, a sua resistencia a degradacao e, com baixo risco de contaminacao do lencol freatico para as condicoes apresentadas. Para todos os tratamentos, houve maior retencao do principio ativo dos inseticidas nas camadas mais superficiais (0 a 15 cm) do solo
The zika virus disease: An overview
The zika virus, another re-emerging Flavivirus transmitted to humans by mosquitoes, is responsible for the most recent fever outbreak in the Americas and the Pacific, starting in 2015. The immunologically naïve population in the Americas favors the spread of epidemics. The zika fever is characterized by febrile illness, malaise, conjunctivitis and a maculopapular rash. Similar to other arboviroses recently spread in the Americas, there is no specific or effective antiviral therapy and vaccines are still in trials. The only effective preventive measures consist of individual protection against mosquito bites and vector control. This febrile illness increases the epidemiological and public health challenge existing in America, where the population is already fighting against dengue and chikungunya fever. Disease prevention is important due to
the economic burden it entails. The fact of sexual and transfusion virus transmission is a great challenge to overcome. Doctors need to distinguish between dengue, chikungunya and other diseases to give a successful treatment and prevent the disease spreading
Electronic structure of wurtzite and zinc-blende AlN
The electronic structure of AlN in wurtzite and zinc-blende phases is studied
experimentally and theoretically. By using x-ray emission spectroscopy, the Al
3p, Al 3s and N 2p spectral densities are obtained. The corresponding local and
partial theoretical densities of states (DOS), as well as the total DOS and the
band structure, are calculated by using the full potential linearized augmented
plane wave method, within the framework of the density functional theory. There
is a relatively good agreement between the experimental spectra and the
theoretical DOS, showing a large hybridization of the valence states all along
the valence band. The discrepancies between the experimental and theoretical
DOS, appearing towards the high binding energies, are ascribed to an
underestimation of the valence band width in the calculations. Differences
between the wurtzite and zinc-blende phases are small and reflect the slight
variations between the atomic arrangements of both phases
The intrinsic dimensionality of spectro-polarimetric data
The amount of information available in spectro-polarimetric data is
estimated. To this end, the intrinsic dimensionality of the data is inferred
with the aid of a recently derived estimator based on nearest-neighbor
considerations and obtained applying the principle of maximum likelihood. We
show in detail that the estimator correctly captures the intrinsic dimension of
artificial datasets with known dimension. The effect of noise in the estimated
dimension is analyzed thoroughly and we conclude that it introduces a positive
bias that needs to be accounted for. Real simultaneous spectro-polarimetric
observations in the visible 630 nm and the near-infrared 1.5 microns spectral
regions are also investigated in detail, showing that the near-infrared dataset
provides more information of the physical conditions in the solar atmosphere
than the visible dataset. Finally, we demonstrate that the amount of
information present in an observed dataset is a monotonically increasing
function of the number of available spectral lines.Comment: 12 pages, 7 figures, accepted for publication in the Astrophysical
Journa
Baryon Resonances
In this talk I show recent results on how many excited baryon resonances
appear as systems of one meson and one baryon, or two mesons and one baryon,
with the mesons being either pseudoscalar or vectors. Connection with
experiment is made including a discussion on old predictions and recent results
for the photoproduction of the resonance, as well as the
prediction of one baryon state around 1920 MeV which might have been
seen in the reaction.Comment: Talk given at the 10th International Conference on Hypernuclear and
Strange Particle Physics, Tokai, Japan, Sptember 200
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