3,060 research outputs found

    Hadronic eta and eta-prime decays

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    The hadronic decays eta, eta-prime -> 3 pi and eta-prime -> eta pi pi are investigated within the framework of U(3) chiral effective field theory in combination with a relativistic coupled-channels approach. Final state interactions are included by deriving s- and p-wave interaction kernels for meson-meson scattering from the chiral effective Lagrangian and iterating them in a Bethe-Salpeter equation. Very good overall agreement with currently available data on decay widths and spectral shapes is achieved.Comment: 28 pages, 5 figures, 8 table

    Chiral Corrections to Lattice Calculations of Charge Radii

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    Logarithmic divergences in pion and proton charge radii associated with chiral loops are investigated to assess systematic uncertainties in current lattice determinations of charge radii. The chiral corrections offer a possible solution to the long standing problem of why present lattice calculations yield proton and pion radii which are similar in size.Comment: PostScript file only. Ten pages. Figures included. U. of MD Preprint #92-19

    Chiral two-loop pion-pion scattering parameters from crossing-symmetric constraints

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    Constraints on the parameters in the one- and two-loop pion-pion scattering amplitudes of standard chiral perturbation theory are obtained from explicitly crossing-symmetric sum rules. These constraints are based on a matching of the chiral amplitudes and the physical amplitudes at the symmetry point of the Mandelstam plane. The integrals over absorptive parts appearing in the sum rules are decomposed into crossing-symmetric low- and high-energy components and the chiral parameters are finally related to high-energy absorptive parts. A first application uses a simple model of these absorptive parts. The sensitivity of the results to the choice of the energy separating high and low energies is examined with care. Weak dependence on this energy is obtained as long as it stays below ~560 MeV. Reliable predictions are obtained for three two-loop parameters.Comment: 23 pages, 4 figures in .eps files, Latex (RevTex), our version of RevTex runs under Latex2.09, submitted to Phys. Rev. D,minor typographical corrections including the number at the end of the abstract, two sentences added at the end of Section 5 in answer to a referee's remar

    Integrating out the heaviest quark in N--flavour ChPT

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    We extend a known method to integrate out the strange quark in three flavour chiral perturbation theory to the context of an arbitrary number of flavours. As an application, we present the explicit formulae to one--loop accuracy for the heavy quark mass dependency of the low energy constants after decreasing the number of flavours by one while integrating out the heaviest quark in N--flavour chiral perturbation theory.Comment: 18 pages, 1 figure. Text and references added. To appear in EPJ

    Questions éthiques et cliniques posées par l'adoption de l'initiative sur l'internement à vie des délinquants particulièrement dangereux par le peuple suisse

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    Une initiative populaire se concluant par un vote national a conduit le peuple suisse à demander une modification de sa constitution pour permettre d'interner définitivement certains délinquants particulièrement dangereux. Une fois la décision prise, aucune véritable réévaluation de la situation ne pourra être effectuée. Cette décision se basera principalement sur l'expertise psychiatrique qui devra se prononcer sur le caractère inamendable ou inaccessible à tout traitement de tels sujets. Cet article présente l'historique de la démarche populaire qui a conduit à ce vote et la manière dont l'Etat suisse a rendu compte de cette votation en tentant de l'inscrire dans son code pénal. Pourtant le texte voté se présentait d'une manière telle qu'il rendait impossible son inscription autant dans un discours juridique que dans un discours psychiatrique. Il confronte maintenant les praticiens à des questions éthiques majeures. Doit-on accepter de s'inscrire dans un tel processus pénal? Peut-on valider par une expertise un pronostic qui engage la vie entière d'une personne lorsque l'on connaît le caractère incertain et donc discutable des approches prédictives? Comment tout un Etat de droit a-t-il pu laisser se développer un tel leurre quant à la place de la psychiatrie dans la cité? [Auteurs]]]> Sex Offenses; Commitment of Mentally Ill; Forensic Psychiatry fre oai:serval.unil.ch:BIB_43D14F96D4A2 2022-05-07T01:16:46Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_43D14F96D4A2 ECIL-6 guidelines for the treatment of invasive candidiasis, aspergillosis and mucormycosis in leukemia and hematopoietic stem cell transplant patients. info:doi:10.3324/haematol.2016.152900 info:eu-repo/semantics/altIdentifier/doi/10.3324/haematol.2016.152900 info:eu-repo/semantics/altIdentifier/pmid/28011902 Tissot, F. Agrawal, S. Pagano, L. Petrikkos, G. Groll, A.H. Skiada, A. Lass-Flörl, C. Calandra, T. Viscoli, C. Herbrecht, R. info:eu-repo/semantics/review article 2017-03 Haematologica, vol. 102, no. 3, pp. 433-444 info:eu-repo/semantics/altIdentifier/eissn/1592-8721 urn:issn:0390-6078 <![CDATA[The European Conference on Infections in Leukemia (ECIL) provides recommendations for diagnostic strategies and prophylactic, pre-emptive or targeted therapy strategies for various types of infection in patients with hematologic malignancies or hematopoietic stem cell transplantation recipients. Meetings are held every two years since 2005 and evidence-based recommendations are elaborated after evaluation of the literature and discussion among specialists of nearly all European countries. In this manuscript, the ECIL group presents the 2015-update of the recommendations for the targeted treatment of invasive candidiasis, aspergillosis and mucormycosis. Current data now allow a very strong recommendation in favor of echinocandins for first-line therapy of candidemia irrespective of the underlying predisposing factors. Anidulafungin has been given the same grading as the other echinocandins for hemato-oncological patients. The beneficial role of catheter removal in candidemia is strengthened. Aspergillus guidelines now recommend the use of either voriconazole or isavuconazole for first-line treatment of invasive aspergillosis, while first-line combination antifungal therapy is not routinely recommended. As only few new data were published since the last ECIL guidelines, no major changes were made to mucormycosis recommendations

    BARYON-BARYON INTERACTIONS IN LARGE N_C CHIRAL PERTURBATION THEORY

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    Interactions of two baryons are considered in large NCN_C chiral perturbation theory and compared to the interactions derived from the Skyrme model. Special attention is given to a torus-like configuration known to be present in the Skyrme model.Comment: 18 pages, REVTEX, 8 uuencoded PS figures appende

    Isospin Violation in Chiral Perturbation Theory and the Decays \eta \ra \pi \ell \nu and \tau \ra \eta \pi \nu

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    I discuss isospin breaking effects within the standard model. Chiral perturbation theory presents the appropriate theoretical framework for such an investigation in the low--energy range. Recent results on the electromagnetic contributions to the masses of the pseudoscalar mesons and the K3K_{\ell 3} amplitudes are reported. Using the one--loop formulae for the η3\eta_{\ell 3} form factors, rather precise predictions for the decay rates of ηπν\eta \rightarrow \pi \ell \nu can be obtained. Finally, I present an estimate of the \tau \ra \eta \pi \nu branching ratio derived from the dominant meson resonance contributions to this decay.Comment: 10 pages, latex, one figure available upon reques

    Sigma-term physics in the perturbative chiral quark model

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    We apply the perturbative chiral quark model (PCQM) at one loop to analyse meson-baryon sigma-terms. Analytic expressions for these quantities are obtained in terms of fundamental parameters of low-energy pion-nucleon physics (weak pion decay constant, axial nucleon coupling, strong pion-nucleon form factor) and of only one model parameter (radius of the nucleonic three-quark core). Our result for the piN sigma term of about 45 MeV is in good agreement with the value deduced by Gasser, Leutwyler and Sainio using dispersion-relation techniques and exploiting the chiral symmetry constraints.Comment: 19 pages, LaTeX-file, 2 Figure

    Baryon magnetic moments and sigma terms in lattice-regularized chiral perturbation theory

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    An SU(3) chiral Lagrangian for the lightest decuplet of baryons is constructed on a discrete lattice of spacetime points, and is added to an existing lattice Lagrangian for the lightest octets of mesons and baryons. A nonzero lattice spacing renders all loop integrations finite, and the continuum limit of any physical observable is identical to the result obtained from dimensional regularization. Chiral symmetry and gauge invariance are preserved even at nonzero lattice spacing. Specific calculations discussed here include the non-renormalization of a conserved vector current, the magnetic moments of octet baryons, and the pi N and KN sigma terms that relate to the nucleon's strangeness content. The quantitative difference between physics at a nonzero lattice spacing and physics in the continuum limit is easily computed, and it represents an expectation for the size of discretization errors in corresponding lattice QCD simulations.Comment: 19 pages, 5 figures, one paragraph added to introduction, to appear in Phys Rev

    Contributions of order O(mquark2){\cal O}(m_{\rm quark}^2) to K3K_{\ell 3} form factors and unitarity of the CKM matrix

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    The form factors for the K3K_{\ell 3} semileptonic decay are computed to order O(p4)O(p^4) in generalized chiral perturbation theory. The main difference with the standard O(p4)O(p^4) expressions consists in contributions quadratic in quark masses, which are described by a single divergence-free low-energy constant, A3A_3. A new simultaneous analysis is presented for the CKM matrix element VusV_{us}, the ratio FK/FπF_K/F_{\pi}, K3K_{\ell 3} decay rates and the scalar form factor slope λ0\lambda_0. This framework easily accommodates the precise value for VudV_{ud} deduced from superallowed nuclear β\beta-decays
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