8,525 research outputs found
On the Potential of Leptonic Minimal Flavour Violation
Minimal Flavour Violation can be realized in several ways in the lepton
sector due to the possibility of Majorana neutrino mass terms. We derive the
scalar potential for the fields whose background values are the Yukawa
couplings, for the simplest See-Saw model with just two right-handed neutrinos,
and explore its minima. The Majorana character plays a distinctive role: the
minimum of the potential allows for large mixing angles -in contrast to the
simplest quark case- and predicts a maximal Majorana phase. This points in turn
to a strong correlation between neutrino mass hierarchy and mixing pattern.Comment: 6 pages; version published on Physics Letters
Revisiting Minimal Lepton Flavour Violation in the Light of Leptonic CP Violation
The Minimal Lepton Flavour Violation (MLFV) framework is discussed after the
recent indication for CP violation in the leptonic sector. Among the three
distinct versions of MLFV, the one with degenerate right-handed neutrinos will
be disfavoured, if this indication is confirmed. The predictions for leptonic
radiative rare decays and muon conversion in nuclei are analysed, identifying
strategies to disentangle the different MLFV scenarios. The claim that the
present anomalies in the semi-leptonic -meson decays can be explained within
the MLFV context is critically re-examined concluding that such an explanation
is not compatible with the present bounds from purely leptonic processes.Comment: 36 pages, 4 figures. V2: References added; version accepted for
publication on JHE
El programa de mejora genética de Pinus pinaster en Galicia
El pino marÃtimo es una de las especies más
importantes del sector forestal gallego. Fruto de esta
importancia, desde los años 80 se lleva a cabo un
programa de mejora cuyo fin último es el
abastecimiento de semilla de alta calidad genética
pasa su uso en repoblación. En este trabajo se
revisan las actuaciones realizadas al respecto tanto
en la zona costera como en el interior de Galicia. Se
describe el dispositivo experimental del programa,
los objetivos y la estrategia de mejora, los resultados
más relevantes alcanzados hasta la fecha, asà como
la planificación de las actuaciones futuras. Aunque
el programa se centra en caracteres clásicos como la
productividad y la rectitud del fuste, se discuten
también los resultados obtenidos y las posibilidades
de mejora de otros caracteres de interés como la
resistencia a patologÃas y plagas, la eficiencia
nutricional o la calidad de madera._____________________________________Maritime pine is one the most important forest-tree
species in Galicia. A breeding program was started
in the 80’s with the aim to provide genetic improved
seed to be use in reforestation. In the present paper
we review all the activities done to date, both in the
coastal and interior area of Galicia, describing the
experimental device, the breeding objectives and
breeding strategy, presenting the main results
achieved, and advancing further activities of the
program. Although the breeding program was
focused on classical traits such productivity and
stem straightness, results and breeding possibilities
of other traits such as pest and disease resistance,
nutritional efficiency and wood quality are also
discussed
Study of thermal protection requirements for a lifting body entry vehicle suitable for near-earth missions Final report
Reentry and abort trajectory analyses, and thermal protection requirements for lifting body entry vehicle
External Validation of Voter Turnout Models by Concealed Parameter Recovery
We conduct a model validation analysis of several behavioral models of voter turnout, using laboratory data. We call our method of model validation concealed parameter recovery, where estimation of a model is done under a veil of ignorance about some of the experimentally controlled parameters — in this case voting costs. We use quantal response equilibrium as the underlying, common structure for estimation, and estimate models of instrumental
voting, altruistic voting, expressive voting, and ethical voting. All the models except the ethical model recover the concealed parameters reasonably well. We also report the results of a counterfactual analysis based on the recovered parameters, to compare the policy implications of the different models about the cost of a subsidy to increase turnout
Multiple Components in Narrow Planetary Rings
The phase-space volume of regions of regular or trapped motion, for bounded
or scattering systems with two degrees of freedom respectively, displays
universal properties. In particular, drastic reductions in the volume (gaps)
are observed at specific values of a control parameter. Using the stability
resonances we show that they, and not the mean-motion resonances, account for
the position of these gaps. For more degrees of freedom, exciting these
resonances divides the regions of trapped motion. For planetary rings, we
demonstrate that this mechanism yields rings with multiple components.Comment: 4 pages, 7 figures (some in colors
Novel Cellular and Molecular Interactions During Limb Development, Revealed from Studies on the Split Hand Foot Congenital Malformation
The embryonic development of the limbs is widely used as a paradigm for the comprehension of the cellular processes and molecular mechanisms underlying organogenesis and pattern formation. The chick, mouse and (recently), zebrafish embryos are excellent models, for the ease of experimental manipulation and the availability of several mutant strains with limb malformation defects
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