207 research outputs found
Isgur-Wise functions, Bjorken-Uraltsev Sum Rules and their Lorentz group interpretation, In Memoriam Nikolai Uraltsev
In the heavy quark limit of QCD, using the Operator Product Expansion and the
non-forward amplitude, as proposed by Nikolai Uraltsev, we formulate sum rules
that generalize Bjorken and Uraltsev sum rules. We recover the Uraltsev lower
bound for the slope of the Isgur-Wise (IW) function, that we generalize to
higher derivatives. We show that these results have a clear interpretation in
terms of the Lorentz group, since the IW function is given by an overlap
between the initial and final light clouds, related by Lorentz transformations.
Both the Lorentz group and the Sum Rules approach are equivalent. Moreover, we
formulate an integral representation of the IW function with a positive
measure. Inverting this integral formula, we obtain the measure in terms of the
IW function, allowing to formulate criteria to decide if a given ansatz for the
IW function is compatible or not with the sum rule constraints. We compare
these theoretical constraints to some forms proposed in the literature
The controversy about "1/m_Q duality violation" ; a quark model point of view
A detailed discussion based on exact calculations, possible in the non
relativistic quark model, is given to show that there is no 1/m_Q term in the
heavy quark expansion of totally integrated semileptonic decay rates. More
generally, it is shown that OPE holds with very few terms in the expansion, at
least in the harmonic oscillator model.Comment: 10 pages, full articl
Le retour de la pièce esquillée !
pdf déposé avec autorisation de l'éditeurNational audienceLes auteurs s'interrogent sur les outillages riches en pièces esquillées, rassemblent des données sur leur situation géographique et passent en revue les différentes hypothèses technologiques et fonctionnelles
Election turnout statistics in many countries: similarities, differences, and a diffusive field model for decision-making
We study in details the turnout rate statistics for 77 elections in 11
different countries. We show that the empirical results established in a
previous paper for French elections appear to hold much more generally. We find
in particular that the spatial correlation of turnout rates decay
logarithmically with distance in all cases. This result is quantitatively
reproduced by a decision model that assumes that each voter makes his mind as a
result of three influence terms: one totally idiosyncratic component, one
city-specific term with short-ranged fluctuations in space, and one long-ranged
correlated field which propagates diffusively in space. A detailed analysis
reveals several interesting features: for example, different countries have
different degrees of local heterogeneities and seem to be characterized by a
different propensity for individuals to conform to the cultural norm. We
furthermore find clear signs of herding (i.e. strongly correlated decisions at
the individual level) in some countries, but not in others.Comment: 15 pages, 9 figures, 7 table
Multiscale structures of lipids in foods as parameters affecting fatty acid bioavailability and lipid metabolism.
This review is respectfully dedicated to the memory of Michel Ollivon, Research Director at CNRS (Châtenay-Malabry, France), outstanding physico-chemist specialist of lipid organization, recipient of the Hilditch Memorial Lecture award, who was the initiator of the network RMT LISTRAL. We are also sadly paying tribute to Jean-Luc Vendeuvre, Food Engineer at the French Pork and Pig Institute (IFIP, Maisons-Alfort, France), outstanding expert in meat products who participated actively in RMT LISTRAL and provided unpublished data for figures in the present review, who passed away during review submission. RMT LISTRAL: Mixed Technological Network combining academic and industrial partners, devoted to the enhancement and divulgation of knowledge regarding structured dietary lipids.International audienceOn a nutritional standpoint, lipids are now being studied beyond their energy content and fatty acid (FA) profiles. Dietary FA are building blocks of a huge diversity of more complex molecules such as triacylglycerols (TAG) and phospholipids (PL), themselves organised in supramolecular structures presenting different thermal behaviours. They are generally embedded in complex food matrixes. Recent reports have revealed that molecular and supramolecular structures of lipids and their liquid or solid state at the body temperature influence both the digestibility and metabolism of dietary FA. The aim of the present review is to highlight recent knowledge on the impact on FA digestion, absorption and metabolism of: (i) the intramolecular structure of TAG; (ii) the nature of the lipid molecules carrying FA; (iii) the supramolecular organization and physical state of lipids in native and formulated food products and (iv) the food matrix. Further work should be accomplished now to obtain a more reliable body of evidence and integrate these data in future dietary recommendations. Additionally, innovative lipid formulations in which the health beneficial effects of either native or recomposed structures of lipids will be taken into account can be foreseen
Resilient Computing Curriculum
This Deliverable presents the MSc Curriculum in Resilient Computing suggested by ReSIST. It includes the description of the syllabi for all the courses in the two semesters of the first year, those for the common courses in semester 3 in the second year together with an exemplification of possible application tracks with the related courses. This MSc curriculum has been updated and
completed taking advantage of a large open discussion inside and outside ReSIST. This MSc Curriculum is on-line on the official ReSIST web site, where all information is available together with all the support material generated by ReSIST and all other relevant freely available support material.European Commission through NoE IST-4-026764-NOE (ReSIST
Resilient Computing Courseware
This Deliverable describes the courseware in support to teaching Resilient Computing
in a Curriculum for an MSc track following the scheme of the Bologna process. The development of the supporting material for such a curriculum has required a rather intensive activity that involved not only the partners in ReSIST but also a much
larger worldwide community with the aim of identifying available updated support
material that can be used to build a progressive and methodical line of teaching to accompany students and interested persons in a profitable learning process. All this material is on-line on the official ReSIST web site http://www.resistnoe.org/, can be viewed and downloaded for use in a class and constitutes, at our knowledge, the first, almost comprehensive attempt, to build a database of support material related to Dependable and Resilient Computing.European Commission through NoE IST-4-026764-NOE (ReSIST
Chapitre VI. De la violence à la régulation concertée des conflits
L’accroissement des populations de sangliers et de leurs impacts socio-économiques, et le fait que l’activité cynégétique est aujourd’hui moins comprise, sont sources de conflits toujours plus nombreux. Avec le développement d’une société de loisirs, l’attractivité de l’espace rural et les nouveaux modes de vie, de nouvelles pratiques territoriales ont fait leur apparition et ont dessiné de nouveaux territoires. L’enjeu que représente l’espace rural a pour conséquence une confrontation entre ..
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