134 research outputs found

    The Experimental Status of the Standard Electroweak Model at the End of the LEP-SLC Era

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    A method is proposed to calculate the confidence level for agreement of data with the Standard Model (SM) by combining information from direct and indirect Higgs Boson searches. Good agreement with the SM is found for mH120m_H \simeq 120 GeV using the observables most sensitive to mHm_H: AlA_l and mWm_W. In particular, quantum corrections, as predicted by the SM, are observed with a statistical significance of forty-four standard deviations. However, apparent deviations from the SM of 3.7σ\sigma and 2.8σ\sigma are found for the Zννˉ\nu \bar{\nu} and right-handed Zbbˉ\bar{{\rm b}} couplings respectively. The maximum confidence level for agreement with the SM of the entire data set considered is 0.006\simeq 0.006 for mH180m_H \simeq 180 GeV. The reason why confidence levels about an order of magnitude higher than this have been claimed for global fits to similar data sets is explained.Comment: 47 pages, 8 figures, 24 tables. An in-depth study of statistical issues related to the comparison of precision EW data to the S

    Nucleon form factors, B-meson factories and the radiative return

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    The feasibility of a measurement of the electric and magnetic nucleon form factors at BB-meson factories through the radiative return is studied. Angular distributions allow a separation of the contributions from the two form factors. The distributions are presented for the laboratory and the hadronic rest frame, and the advantages of different coordinate systems are investigated. It is demonstrated that Q2Q^2 values up to 8 or even 9 GeV2^2 are within reach. The Monte Carlo event generator PHOKHARA is extended to nucleon final states, and results are presented which include Next-to-Leading Order radiative corrections from initial-state radiation. The impact of angular cuts on rates and distributions is investigated and the relative importance of radiative corrections is analysed.Comment: 9 pages, 11 figures. Final version to appear in Eur. Phys. J.

    Zemach and magnetic radius of the proton from the hyperfine splitting in hydrogen

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    The current status of the determination of corrections to the hyperfine splitting of the ground state in hydrogen is considered. Improved calculations are provided taking into account the most recent value for the proton charge radius. Comparing experimental data with predictions for the hyperfine splitting, the Zemach radius of the proton is deduced to be 1.045(16)1.045(16) fm. Employing exponential parametrizations for the electromagnetic form factors we determine the magnetic radius of the proton to be 0.778(29)0.778(29) fm. Both values are compared with the corresponding ones derived from the data obtained in electron-proton scattering experiments and the data extracted from a rescaled difference between the hyperfine splittings in hydrogen and muonium

    Comprehensive testing of NedWind 12-meter wind turbine blades at NREL

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    This paper describes the structural testing of two NedWind 25, 12-m blades at the National Renewable Energy Laboratory (NREL). The tests were conducted under the Standards, Measurement and Testing (SMT) Program in conjunction with tests conducted by four European laboratories to develop a common database of blade testing methods. All of the laboratories tested duplicate copies of blades taken from series production. Blade properties, including weight, center of gravity, natural frequencies, and damping were determined. Static load tests were performed at 110% of the extreme design load for strain verification. NREL performed single-axis and two-axis fatigue tests using business-as-usual testing practices. The single-axis test combined equivalent life loading for the edge and flap spectra into a single resultant load. The two-axis test applied the edge and flap components independently at a phase angle of 90°. Damage areas were observed at (1) the trailing edge, which cracked near the maximum chord; (2) between the steel root collar and the composite, where circumferential cracking was noted; and (3) along the top of the spar between the 2500-mm and 4200-mm stations, where a notable increase in acoustic emissions was detected. NREL observed that the onset of visible damage occurred earlier in the single-axis test

    Міжнародний досвід боротьби з корупцією у правоохоронних органах

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    Головко, Б. Г. Міжнародний досвід боротьби з корупцією у правоохоронних органах / Б. Г. Ващенко // Правова наука і державотворення в Україні в контексті правової інтеграції: матеріали ХІІ Міжнар. наук.-практ. конф. (м. Суми, 24-25 трав. 2019 р.) / МВС України, Сум. філія Харків. нац. ун-ту внутр. справ. – Суми: Видав. дім «Ельдорадо», 2019. – С. 67-70.Зазначено, що проблеми, пов’язані з попередженням і припиненням корупції в поліції, актуальні не тільки для нашої країни. Різноманітні методи і способи протидії корупції, що використовуються в інших країнах, необхідно вивчати, критично аналізувати і використовувати в поліції України. Багато держав сформували універсальні адміністративно-правові засоби попередження і припинення корупції, які не залежать від національної специфіки.It was noted that the problems associated with the prevention and suppression of corruption in the police are relevant not only for our country. Various methods and means of combating corruption used in other countries need to be studied, critically analyzed and used in the police of Ukraine. Many states have formed universal administrative and legal means of preventing and stopping corruption, which do not depend on national specifics.Отмечено, что проблемы, связанные с предупреждением и пресечением коррупции в полиции, актуальны не только для нашей страны. Различные методы и способы противодействия коррупции, используемые в других странах, необходимо изучать, критично анализировать и использовать в полиции Украины. Многие государства сформировали универсальные административно-правовые средства предупреждения и прекращения коррупции, не зависящие от национальной специфики

    Measurement of the LT-asymmetry in \pi^0 electroproduction at the energy of the \Delta (1232) resonance

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    The reaction p(e,e'p)pi^0 has been studied at Q^2=0.2 (GeV/c)^2 in the region of W=1232 MeV. From measurements left and right of q, cross section asymmetries \rho_LT have been obtained in forward kinematics \rho_LT(\theta_\pi^0=20deg) = (-11.68 +/- 2.36_stat +/- 2.36_sys)$ and backward kinematics \rho_LT(\theta_\pi^0=160deg) =(12.18 +/- 0.27_stat +/- 0.82_sys). Multipole ratios \Re(S_1+^* M_1+)/|M_1+|^2 and \Re(S_0+^* M_1+)/|M_1+|^2 were determined in the framework of the MAID2003 model. The results are in agreement with older data. The unusally strong negative \Re(S_0+^* M_1+)/|M_1+|^2 required to bring also the result of Kalleicher et al. in accordance with the rest of the data is almost excluded.Comment: 7 pages, 7 figures, 4 tables. Changed content. Accepted for publication in EPJ

    Parton distributions incorporating QED contributions

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    We perform a global parton analysis of deep inelastic and related hard-scattering data, including O( QED) corrections to the parton evolution. Although the quality of the fit is essentially unchanged, there are two important physical consequences. First, the different DGLAP evolution of u and d type quarks introduces isospin violation, i.e. up 6= dn, which is found to be unambiguously in the direction to reduce the NuTeV sin2 W anomaly. A second consequence is the appearance of photon parton distributions (x,Q2) of the proton and the neutron. In principle these can be measured at HERA via the deep inelastic scattering processes eN → e X; our predictions are in agreement with the present data

    Geometrical Models for Substitutions

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    International audienceWe consider a substitution associated with the Arnoux-Yoccoz interval exchange transformation (IET) related to the tribonacci substitution. We construct the so-called stepped lines associated with the fixed points of the substitution in the abelianization (symbolic) space. We analyze various projections of the stepped line, recovering the Rauzy fractal, a Peano curve related to work in [Arnoux 88], another Peano curve related to the work of [McMullen 09] and [Lowenstein et al. 07], and also the interval exchange transformation itself

    Determination of water content in clay and organic soil using microwave oven

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    The article deals with the techniques of soil water content determination using microwave radiation. Its practical application would allow solving the problems of resource efficiency in geotechnical survey due to reduction of energy and resource intensity of laboratory analysis as well as its acceleration by means of decreasing labour intensity and, as a result, cost reduction. The article presents a detail analysis of approaches to soil water content determination and soil drying, considers its features and application. The study in soil of different composition, typical for Western Siberia including organic and organic-mineral ones, is a peculiarity of the given article, which makes it rather topical. The article compares and analyzes the results of the investigation into soil water content, which are obtained via conventional techniques and the original one developed by the authors, consisting in microwave drying. The authors also give recommendation on microwave technique application to dry soil

    Amicable pairs and aliquot cycles for elliptic curves

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    An amicable pair for an elliptic curve E/Q is a pair of primes (p,q) of good reduction for E satisfying #E(F_p) = q and #E(F_q) = p. In this paper we study elliptic amicable pairs and analogously defined longer elliptic aliquot cycles. We show that there exist elliptic curves with arbitrarily long aliqout cycles, but that CM elliptic curves (with j not 0) have no aliqout cycles of length greater than two. We give conjectural formulas for the frequency of amicable pairs. For CM curves, the derivation of precise conjectural formulas involves a detailed analysis of the values of the Grossencharacter evaluated at a prime ideal P in End(E) having the property that #E(F_P) is prime. This is especially intricate for the family of curves with j = 0.Comment: 53 page
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