16,433 research outputs found
Closing the Symmetry at Electroweak Scale
We show that some models with gauge
symmetry can be realized at the electroweak scale and that this is a
consequence of an approximate global symmetry. This symmetry
implies a condition among the vacuum expectation value of one of the neutral
Higgs scalars, the 's coupling constant, , the sine of the weak
mixing angle , and the mass of the boson, . In the limit
in which this symmetry is valid it avoids the tree level mixing of the
boson of the Standard Model with the extra boson. We have verified
that the oblique parameter is within the allowed range indicating that the
radiative corrections that induce such a mixing at the 1-loop level are small.
We also show that a custodial symmetry implies that in some of
the models we have to include sterile (singlets of the 3-3-1 symmetry)
right-handed neutrinos with Majorana masses, being the see-saw mechanism
mandatory to obtain light active neutrinos. Moreover, the approximate
symmetry implies that the extra non-standard
particles of these 3-3-1 models can be considerably lighter than it had been
thought before so that new physics can be really just around the corner.Comment: 32 pages, no figure, RevTeX. Some typos correcte
Identificação varietal de algumas videiras cultivadas no Rio Grande do Sul.
Esta publicraçã contém a descrição ampelográfica das copas que comumente apresentam dificuldades para identificação. bem como dos principais porta-enxertos difundidas na MRH 311.bitstream/item/40787/1/cir11.pdf2. ed. rev
Caracterização da macrofauna invertebrada do solo sob diferentes fitofisionomias do Pantanal.
bitstream/item/66197/1/31473.pdfFERTBIO
X, Y and Z States
Many new states in the charmonium mass region were recently discovered by
BaBar, Belle, CLEO-c, CDF, D0, BESIII, LHCb and CMS Collaborations. We use the
QCD Sum Rule approach to study the possible structure of some of these states.Comment: Contribution for the proceedings of the "XII Quark Confinement and
the Hadron Spectrum - CONF12" conferenc
DigitalPinDirector: A digital pinscreen editor for images and realtime animation in low cost personal computers
This paper presents the main characteristics of the traditional Pinscreen, the way it works, its problems and results achieved. The first Digital Pinscreen system is presented, along with its main characteristics and limitations. The rest of the paper describes and presents the DigitalPinDirector: a system that enables a full and true creative access to
the unique visual and animation characteristics of the Pinscreen.info:eu-repo/semantics/publishedVersio
Adubação Verde na Produção Orgânica de Abacaxi na Chapada Diamantina, BA.
A prática da adubação verde promove benefícios ao solo, dentre estes, aumenta os teores de matéria orgânica, favorece a ciclagem de nutrientes e mantém a cobertura do solo. O presente trabalho objetivou avaliar a produção de biomassa vegetal e os estoques de carbono (C) e macronutrientes na matéria seca de diferentes espécies de adubos verdes utilizados em pré-plantio na cultura do abacaxi
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