47 research outputs found
The Landau Pole and decays in the 331 bilepton model
We calculate the decay widths and branching ratios of the extra neutral boson
predicted by the 331 bilepton model in the framework of two
different particle contents. These calculations are performed taken into
account oblique radiative corrections, and Flavor Changing Neutral Currents
(FCNC) under the ansatz of Matsuda as a texture for the quark mass matrices.
Contributions of the order of are obtained in the branching
ratios, and partial widths about one order of magnitude bigger in relation with
other non- and bilepton models are also obtained. A Landau-like pole arise at
3.5 TeV considering the full particle content of the minimal model (MM), where
the exotic sector is considered as a degenerated spectrum at 3 TeV scale. The
Landau pole problem can be avoid at the TeV scales if a new leptonic content
running below the threshold at TeV is implemented as suggested by other
authors.Comment: 20 pages, 5 figures, LaTeX2
Charged lepton electric dipole moments with the localized leptons and the new Higgs doublet in the two Higgs doublet model
We study the lepton electric dipole moments in the split fermion scenario, in
the two Higgs doublet model, where the new Higgs scalars are localized around
the origin in the extra dimension, with the help of the localizer field. We
observe that the numerical value of the electron (muon, tau) electric dipole
moment is at the order of the magnitude of 10^{-31} (10^{-24}, 10^{-22}) (e-cm)
and this quantity is sensitive the new Higgs localization in the extra
dimension.Comment: 20 pages, 7 figure
First observation of the decay and a measurement of the ratio of branching fractions
The first observation of the decay using
data collected by the LHCb detector at a centre-of-mass energy of 7 TeV,
corresponding to an integrated luminosity of 36 pb, is reported. A
signal of events is obtained and the absence of signal is
rejected with a statistical significance of more than nine standard deviations.
The branching fraction is measured relative to
that of : , where the first uncertainty is statistical, the second systematic and
the third is due to the uncertainty on the ratio of the and
hadronisation fractions.Comment: 10 pages, 3 figures, submitted to Phys. Lett. B; ISSN 0370-269
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Estrutura fina do espermatozóide de Mellita quinquiesperforata Leske (Echinodermata) do litoral norte do Brasil Fine structure of the spermatozoon of the Mellita quinquiesperforata (Echinodermata) of the Northern littoral of Brazil
<abstract language="eng">The fine structure of the spermatozoon in the Mellita quinquiesperforata Leske, 1778 was studied. Collected from the Amazon region, were described by light and transmission electron microscopy. The spermatozoon consisted of a acrosome complex, nucleus, four to six mitochondria, two centrioles and flagellum. The acrosome was composed of a acrosome complex, the acrosomal vesicle and the subacrosomal space. The nucleus are composed by dense material. The middle piece contains 4-6 mitochondria which are arranged around the centrioles, the 9p+0, whose axoneme has the classic 9p+2 microtubular construction