147 research outputs found

    The electromagnetic form factors of the Omega in lattice QCD

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    We present results on the Omega baryon electromagnetic form factors using Nf=2+1N_f=2+1 domain-wall fermion configurations for three pion masses in the range of about 350 to 300 MeV. We compare results obtained using domain wall fermions with those of a mixed-action (hybrid) approach, which combine domain wall valence quarks on staggered sea quarks, for a pion mass of about 350 MeV. We pay particular attention in the evaluation of the subdominant electric quadrupole form factor to sufficient accuracy to exclude a zero value, by constructing a sequential source that isolates it from the dominant form factors. The Ω\Omega^- magnetic moment, μΩ\mu_{\Omega^{-}}, the electric charge and magnetic radius, rE0/M12\langle r^{2}_{E0/M1} \rangle, are extracted for these pion masses. The electric quadrupole moment is determined for the first time using dynamical quarks.Comment: 13 pages, 10 Figure

    The Critical Hopping Parameter in O(a) improved Lattice QCD

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    We calculate the critical value of the hopping parameter, κc\kappa_c, in O(a) improved Lattice QCD, to two loops in perturbation theory. We employ the Sheikholeslami-Wohlert (clover) improved action for Wilson fermions. The quantity which we study is a typical case of a vacuum expectation value resulting in an additive renormalization; as such, it is characterized by a power (linear) divergence in the lattice spacing, and its calculation lies at the limits of applicability of perturbation theory. The dependence of our results on the number of colors NN, the number of fermionic flavors NfN_f, and the clover parameter cSWc_{SW}, is shown explicitly. We compare our results to non perturbative evaluations of κc\kappa_c coming from Monte Carlo simulations.Comment: 11 pages, 2 EPS figures. The only change with respect to the original version is inclusion of the standard formulae for the gauge fixing and ghost parts of the action. Accepted for publication in Physical Review

    Nucleon to Delta transition form factors with NF=2+1N_F=2+1 domain wall fermions

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    We calculate the electromagnetic, axial and pseudo-scalar form factors of the Nucleon to Δ(1232)\Delta(1232) transition using two dynamical light degenerate quarks and a dynamical strange quark simulated with the domain wall fermion action. Results are obtained at lattice spacings a=0.114a = 0.114 fm and a=0.084a=0.084 fm, with corresponding pion masses of 330330 MeV and 297297 MeV, respectively. High statistics measurements are achieved by utilizing the coherent sink technique. The dominant electromagnetic dipole form factor, the axial form factors and the pseudo-scalar coupling are extracted to a good accuracy. This allows the investigation of the non-diagonal Goldberger-Treiman relation. Particular emphasis is given on the extraction of the sub-dominant electromagnetic quadrupole form factors and their ratio to the dominant dipole form factor, REMR_{EM} and RSMR_{SM}, measured in experiment.Comment: 31 pages, 10 figure

    Polyphenols: A concise overview on the chemistry, occurrence, and human health

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    This review gives an updated picture of each class of phenolic compounds and their properties. The most common classification implies the subdivision of phenolics in two main groups: flavonoids (e.g., anthocyanins, flavanols, flavanones, flavonols, flavonones, and isoflavones) and non-flavonoids (e.g., phenolic acids, xanthones, stilbens, lignans, and tannins) polyphenols. The great interest in polyphenols is associated with their high potential application for food preservation and for therapeutic beneficial use. The relationship between polyphenol intake and human health has been exploited with special reference to cardiovascular diseases, hypertension, diabetes, metabolic syndrome, obesity, and cancer. The use of current existing databases of bioactive compounds including polyphenols is described as key tools for human health research.info:eu-repo/semantics/publishedVersio

    Downscaling Climate Change Impacts, Socio-Economic Implications and Alternative Adaptation Pathways for Islands and Outermost Regions

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    This book provides a comprehensive overview of the future scenarios of climate change and management concerns associated with climate change impacts on the blue economy of European islands and outermost regions. The publication collects major findings of the SOCLIMPACT project’s research outcomes, aiming to raise social awareness among policy-makers and industry about climate change consequences at local level, and provide knowledge-based information to support policy design, from local to national level. This comprehensive book will also assist students, scholars and practitioners to understand, conceptualize and effectively and responsibly manage climate change information and applied research. This book provides invaluable material for Blue Growth Management, theory and application, at all levels. This first edition includes up-to-date data, statistics, references, case material and figures of the 12 islands case studies. ¨Downscaling climate change impacts, socio-economic implications and alternative adaptation pathways for Islands and Outermost Regions¨ is a must-read book, given the accessible style and breadth and depth with which the topic is dealt. The book is an up-to-date synthesis of key knowledge on this area, written by a multidisciplinary group of experts on climate and economic modelling, and policy design
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