2,448 research outputs found
: Confronting theory and lattice simulations
We consider a recent -matrix analysis by Albaladejo {\it et al.}, [Phys.\
Lett.\ B {\bf 755}, 337 (2016)] which accounts for the and
coupled--channels dynamics, and that successfully describes the
experimental information concerning the recently discovered .
Within such scheme, the data can be similarly well described in two different
scenarios, where the is either a resonance or a virtual state. To
shed light into the nature of this state, we apply this formalism in a finite
box with the aim of comparing with recent Lattice QCD (LQCD) simulations. We
see that the energy levels obtained for both scenarios agree well with those
obtained in the single-volume LQCD simulation reported in Prelovsek {\it et
al.} [Phys.\ Rev.\ D {\bf 91}, 014504 (2015)], making thus difficult to
disentangle between both possibilities. We also study the volume dependence of
the energy levels obtained with our formalism, and suggest that LQCD
simulations performed at several volumes could help in discerning the actual
nature of the intriguing state
Heavy-to-light scalar form factors from Muskhelishvili-Omn\`es dispersion relations
By solving the Muskhelishvili-Omn\`es integral equations, the scalar form
factors of the semileptonic heavy meson decays ,
, and
are simultaneously studied. As input, we
employ unitarized heavy meson-Goldstone boson chiral coupled-channel amplitudes
for the energy regions not far from thresholds, while, at high energies,
adequate asymptotic conditions are imposed. The scalar form factors are
expressed in terms of Omn\`es matrices multiplied by vector polynomials, which
contain some undetermined dispersive subtraction constants. We make use of
heavy quark and chiral symmetries to constrain these constants, which are
fitted to lattice QCD results both in the charm and the bottom sectors, and in
this latter sector to the light-cone sum rule predictions close to as
well. We find a good simultaneous description of the scalar form factors for
the four semileptonic decay reactions. From this combined fit, and taking
advantage that scalar and vector form factors are equal at , we obtain
, and for the involved Cabibbo-Kobayashi-Maskawa (CKM) matrix
elements. In addition, we predict the following vector form factors at :
, ,
and , which might serve as alternatives to determine the CKM elements when
experimental measurements of the corresponding differential decay rates become
available. Finally, we predict the different form factors above the
regions accessible in the semileptonic decays, up to moderate energies
amenable to be described using the unitarized coupled-channel chiral approach.Comment: includes further discussions and references; matches the accepted
versio
Lowest-lying even-parity B ¯ s mesons: heavy-quark spin-flavor symmetry, chiral dynamics, and constituent quark-model bare masses
The discovery of the and resonances in the charmed-strange meson spectra revealed that formerly successful constituent quark models lose predictability in the vicinity of two-meson thresholds. The emergence of non-negligible effects due to meson loops requires an explicit evaluation of the interplay between and Fock components. In contrast to the sector, there is no experimental evidence of bottom–strange states yet. Motivated by recent lattice studies, in this work the heavy-quark partners of the and states are analyzed within a heavy meson chiral unitary scheme. As a novelty, the coupling between the constituent quark-model P-wave scalar and axial mesons and the channels is incorporated employing an effective interaction, consistent with heavy-quark spin symmetry, constrained by the lattice energy levels
Anomalous Nuclear Quantum Effects in Ice
One striking anomaly of water ice has been largely neglected and never
explained. Replacing hydrogen (H) by deuterium (H) causes ice to
expand, whereas the "normal" isotope effect is volume contraction with
increased mass. Furthermore, the anomaly increases with temperature , even
though a normal isotope shift should decrease with and vanish when is
high enough to use classical nuclear motions. In this study, we show that these
effects are very well described by {\it ab initio} density functional theory.
Our theoretical modeling explains these anomalies, and allows us to predict and
to experimentally confirm a counter effect, namely that replacement of O
by O causes a normal lattice contraction.Comment: 5 pages, 3 figure
The 2011 submarine volcanic eruption in El Hierro (Canary Islands)
Forty years after the Teneguía Volcano (La Palma, 1971), a submarine eruption took place off the town of La Restinga, south of El Hierro, the smallest and youngest island of the Canarian Archipelago. Precursors allowed an early detection of the event and its approximate location, suggesting it was submarine. Uncertainties derived from insufficient scientific information available to the authorities during the eruption, leading to disproportionate civil protection measures, which had an impact on the island's economy-based primarily on tourism-while residents experienced extra fear and distress. © 2012 Blackwell Publishing Ltd, The Geologists' Association & The Geological Society of London.Peer Reviewe
The 2011 submarine volcanic eruption in El Hierro (Canary Islands)
Forty years after the Teneguía Volcano (La Palma, 1971), a submarine eruption took place off the town of La Restinga, south of El Hierro, the smallest and youngest island of the Canarian Archipelago. Precursors allowed an early detection of the event and its approximate location, suggesting it was submarine. Uncertainties derived from insufficient scientific information available to the authorities during the eruption, leading to disproportionate civil protection measures, which had an impact on the island's economy-based primarily on tourism-while residents experienced extra fear and distress. © 2012 Blackwell Publishing Ltd, The Geologists' Association & The Geological Society of London.Peer Reviewe
3849_REDITS. Red Interuniversitaria para la didáctica en Trabajo Social
El presente trabajo se enmarca en el seno del Programa de Redes-ICE de investigación en docencia universitaria del Vicerrectorado de Calidad e Innovación Educativa-Instituto de Ciencias de la Educación de la Universidad de Alicante (convocatoria 2016-17), “Ref.: 3849 REDITS”. Como primera estrategia partimos de la revisión de la literatura especializada recogiendo lo que venimos trabajando sobre competencias en Trabajo Social y promoción del trabajo colaborativo, e incorporando los aspectos relativos a la supervisión, estableciendo la diferencia entre la supervisión educativa y la supervisión profesional. Se realizó una revisión de la producción desarrollada por REDITS, a efectos de ir procurando no solo la homologación de criterios sino la construcción de estrategias de trabajo a partir de los resultados de las supervisiones. La segunda estrategia consistió en el seguimiento de experiencias puntuales de docencia en las que la red constituye un espacio de construcción de alternativas a partir de poner en común casos de cada universidad buscando puntos de convergencia y alternativas de trabajo. Se trabajó particularmente aspectos relativos a la educación inclusiva en el ámbito universitario. Como tercera estrategia se realizo un grupo de discusión de profesorado y se pasaron evaluaciones abiertas al alumnado sobre los tipos de supervisión en el proceso de enseñanza aprendizaje
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