119,044 research outputs found

    A note on q-Bernstein polynomials

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    In this paper we constructed new q-extension of Bernstein polynomials. Fron those q-Berstein polynomials, we give some interesting properties and we investigate some applications related this q-Bernstein polynomials.Comment: 13 page

    The Effects of the Massless O(alpha_s^2), O(\alpha\alpha_s), O(\alpha^2) QCD and QED Corrections and of the Massive Contributions to Gamma(H^0\rightarrow b\overline{b})

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    We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of H0→bb‾H^0\rightarrow b\overline{b} process in the region 50 GeV<MH≤2MW50\ GeV< M_H\leq 2M_W. We calculate the order O(αs2)O(\alpha_s^2)-contributions to the expression for ΓHbb‾\Gamma_{Hb\overline{b}} through the pole quark mass and demonstrate that they are important for the elimination of the numerical difference between the corresponding expression and the one through the running bb-quark mass. The order O(ααs)O(\alpha\alpha_s) and O(α2)O(\alpha^2) massless and order O(mb2/MH2)O(m_b^2/M_H^2) massive corrections to ΓHbb‾\Gamma_{Hb\overline{b}} are also calculated. The importance of the latter contributions for modeling of the threshold effects is demonstrated. The troubles with identifying of the 4 recent L3 events e+e−→l+l−γγe^+e^-\rightarrow l^+l^-\gamma\gamma with the decay of a Standard Higgs boson are discussed.Comment: 16 pages, 6 figures (can be optained by mail after the request from the authers, e-mails: [email protected]; [email protected]); LATEX, modified version of ENSLAPP.-A.-407/92 preprin

    Photoproduction off the nucleon revisited: Evidence for a narrow N(1688) resonance?

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    Revised analysis of Σ\Sigma beam asymmetry for the η\eta photoproduction on the free proton reveals a structure at W∼1.69W\sim 1.69 GeV. Fit of the experimental data based on the E429 solution of the SAID partial wave analysis suggests a narrow (Γ≤25\Gamma \leq 25 MeV) resonance. Possible candidates are P11,P13P_{11}, P_{13}, or D13D_{13} resonances. The result is considered in conjunction with the recent evidence for a bump-like structure at W∼1.67−1.68W\sim 1.67 - 1.68 GeV in the quasi-free η\eta photoproduction on the neutron.Comment: Contribution to the Workshop on the Physics of the Excited Nucleons NSTAR2007, Bonn, Germany, Sept. 5 - 8 2007. To be published in Eur.Phys.J.
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