2,408 research outputs found

    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

    Thin-disk laser pump schemes for large number of passes and moderate pump source quality

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    Novel thin-disk laser pump layouts are proposed yielding an increased number of passes for a given pump module size and pump source quality. These novel layouts result from a general scheme which bases on merging two simpler pump optics arrangements. Some peculiar examples can be realized by adapting standard commercially available pump optics simply by intro ducing an additional mirror-pair. More pump passes yield better efficiency, opening the way for usage of active materials with low absorption. In a standard multi-pass pump design, scaling of the number of beam passes brings ab out an increase of the overall size of the optical arrangement or an increase of the pump source quality requirements. Such increases are minimized in our scheme, making them eligible for industrial applicationsComment: 16 pages, 9 figure

    Baryon chiral perturbation theory with virtual photons and leptons

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    We construct the general pion-nucleon SU(2) Lagrangian including both virtual photons and leptons for relativistic baryon chiral perturbation theory up to fourth order. We include the light leptons as explicit dynamical degrees of freedom by introducing new building blocks which represent these leptons.Comment: 11 page

    Contribution of higher meson resonances to the electromagnetic π\pi-meson mass difference

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    Modifications of the DGMLY relation for calculation of electromagnetic π\pi-meson mass difference based on the Chiral Symmetry Restoration phenomenon at high energies as well as the Operator Product Expansion of quark densities for vector (ρ\rho) and axial-vector (a1a_1) meson fields difference are proposed. In the calculations higher meson resonances in vector and axial-vector channels are taken into account. It is shown that the inclusion of the first ρ\rho and a1a_1 radial excitations improves the results for electromagnetic π\pi-meson mass difference as compared with the previous ones. Estimations on the electromagnetic ρ\rho and a1a_1-meson decay constants and the constant L10L_{10} of effective chiral Lagrangian are obtained from the generalized Weinberg sum rules.Comment: Latex2e, 10 pages, submitted to Yad. Phy

    Strategies to promote translational research within the European Organisation for Research and Treatment of Cancer (EORTC) Head and Neck Cancer Group: a report from the Translational Research Subcommittee

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    Head and neck squamous cell cancer (HNSCC) is the sixth leading cause of cancer-related deaths worldwide. These tumors are commonly diagnosed at advanced stages and mortality rates remain high. Even cured patients suffer the consequences of aggressive treatment that includes surgery, chemotherapy, and radiotherapy. In the past, in clinical trials, HNSCC was considered as a single disease entity. Advances in molecular biology with the development of genomic and proteomic approaches have demonstrated distinct prognostic HNSCC patient subsets beyond those defined by traditional clinical-pathological factors such as tumor subsite and stage [Cho W (ed). An Omics Perspective on Cancer Research. New York/Berlin: Springer 2010]. Validation of these biomarkers in large prospective clinical trials is required before their clinical implementation. To promote this research, the European Organisation for Research and Treatment of Cancer (EORTC) Head and Neck Cancer Program will develop the following strategies—(i) biobanking: prospective tissue collection from uniformly treated patients in the setting of clinical trials; (ii) a group of physicians, physician—scientists, and EORTC Headquarters staff devoted to patient-oriented head and neck cancer research; (iii) a collaboration between the basic scientists of the Translational Research Division interested in head and neck cancer research and the physicians of the Head and Neck Cancer Group; and (iv) funding through the EORTC Grant Program and the Network Core Institutions Consortium. In the present report, we summarize our strategic plans to promote head and neck cancer research within the EORTC framewor

    Review of chiral perturbation theory

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    A review of chiral perturbation theory and that of recent developments on the comparison of its predictions with experiment is presented. Some interesting topics with scope for further elaboration are touched upon.Comment: 7 pages in revtex, Invited talk at the workshop, QCD2002, Indian Institute of Technology, Kanpur, November 18-22, 2002, to appear in the proceeding
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