16,230 research outputs found
Electromagnetic Structure of the Pion
In this work, we analyze the electromagnetic structure of the pion. We
calculate its electromagnetic radius and electromagnetic form factor in low and
intermediate momentum range. Such observables are determined by means of a
theoretical model that takes into account the constituent quark and antiquark
of the pion within the formalism of light-front field theory. In particular, we
consider a nonsymmetrical vertex in this model, with which we calculate the
electromagnetic form factor of the pion in an optimized way, so that we obtain
a value closer to the experimental charge radius of the pion. The theoretical
calculations are also compared with the most recent experimental data involving
the pion electromagnetic form factor and the results show very good agreement.Comment: Paper with 4 pages, 1 figure, presented in XII HADRON PHYSICS
Conference - to appear in AIP Conference Proceeding
Sedative and antinociceptive effects of different combinations of detomidine and methadone in standing horses
The importance of measuring skin resistance for electrical nociceptive stimulation in standing horses
The Electromagnetic Form Factor of the Kaon in the Light-Front Approach
The kaon electromagnetic form factor is calculated within a light-front
constituent quark model (LFCQM). The electromagnetic components of the current
are extracted from the Feynman triangle diagram within the light-front
approach. We also obtain the electroweak decay constant and the charge radius
for the kaon in the light-front approach. In this work, the kaon observables
are calculated and a fairly good agreement is obtained with a very higher
accuracy when compared with the experimental data.Comment: Paper with 4 pages, 1 figure, reference: XII HADRON PHYSICS
Conference - to appear in AIP Conference Proceeding
Ocorrência da podridão floral dos citros (Coletotrichum acutatum, Simmonds), em diferentes combinações de copa e porta-enxerto.
A doença Podridão Floral dos Citros (PFC) ou estrelinha como é conhecida pelos produtores é causada pelo fungo Colletotrichum acutatum, Simmonds que produz lesões de coloração alaranjada ou ferruginosa nos botões florais ou nas pétalas, infectando posteriormente o estilo que se desprende, ficando aderidos aos ramos os receptáculos persistentes da flor. Este trabalho objetivou avaliar a incidência do fungo C. acutatum, Simmonds, em flores de copa de lima ácida Tahiti enxertada sobre cinco diferentes porta-enxertos.PDF. 089_1
Magnetic excitations in the spin-1 anisotropic antiferromagnet
The spin-1 anisotropic antiferromagnet NiCl_2-4SC(NH2)_2 exhibits a
field-induced quantum phase transition that is formally analogous to
Bose-Einstein condensation. Here we present results of systematic high-field
electron spin resonance (ESR) experimental and theoretical studies of this
compound with a special emphasis on single-ion two-magnon bound states. In
order to clarify some remaining discrepancies between theory and experiment,
the frequency-field dependence of magnetic excitations in this material is
reanalyzed. In particular, a more comprehensive interpretation of the
experimental signature of single-ion two-magnon bound states is shown to be
fully consistent with theoretical results. We also clarify the structure of the
ESR spectrum in the so-called intermediate phase.Comment: 9 pages, 10 figure
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