13,968 research outputs found

    CHEMICAL AND PHYSICAL CHARACTERISTICS OF M. PSOAS MAIOR FROM ALENTEJANO PIGS AT A VARIOUS LIVE WEIGTHS

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    The present study was carried out to investigate the evolution of biochemical composition and physical traits of the chemical composition and physical characteristics of muscle Psoas major (PM adipose during growth of Alentejano pigs

    The Matrix Element Method and QCD Radiation

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    The matrix element method (MEM) has been extensively used for the analysis of top-quark and W-boson physics at the Tevatron, but in general without dedicated treatment of initial state QCD radiation. At the LHC, the increased center of mass energy leads to a significant increase in the amount of QCD radiation, which makes it mandatory to carefully account for its effects. We here present several methods for inclusion of QCD radiation effects in the MEM, and apply them to mass determination in the presence of multiple invisible particles in the final state. We demonstrate significantly improved results compared to the standard treatment.Comment: 15 pp; v2: references and some clarifications added; v3: discussion of NLO effects, version published in PR

    Gravitation Wave Emission from Radio Pulsars Revisited

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    We report a new pulsar population synthesis based on Monte Carlo techniques, aiming to estimate the contribution of galactic radio pulsars to the continuous gravitational wave emission. Assuming that the rotation periods of pulsars at birth have a Gaussian distribution, we find that the average initial period is 290 ms. The number of objects with periods equal to or less than 0.4 s, and therefore capable of being detected by an interferometric gravitational antenna like VIRGO, is of the order of 5100-7800. With integration times lasting between 2 and 3 yr, our simulations suggest that about two detections should be possible, if the mean equatorial ellipticity of the pulsars is ϵ\epsilon =10−6^{-6}. A mean ellipticity an order of magnitude higher increases the expected number of detections to 12-18, whereas for ϵ<10−6\epsilon < 10^{-6}, no detections are expectedComment: accepted for publication in A&A, 9 pages, 8 figure

    Subleading Logarithmic QED Initial State Corrections to e+e−→γ∗/Z0∗e^+e^- \rightarrow \gamma^*/{Z^{0}}^* to O(α6L5)O(\alpha^6 L^5)

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    Using the method of massive operator matrix elements, we calculate the subleading QED initial state radiative corrections to the process e+e−→γ∗/Z∗e^+e^- \rightarrow \gamma^*/Z^* for the first three logarithmic contributions from O(α3L3),O(α3L2),O(α3L)O(\alpha^3 L^3), O(\alpha^3 L^2), O(\alpha^3 L) to O(α5L5),O(α5L4),O(α5L3)O(\alpha^5 L^5), O(\alpha^5 L^4), O(\alpha^5 L^3) and compare their effects to the leading contribution O(α6L6)O(\alpha^6 L^6) and one more subleading term O(α6L5)O(\alpha^6 L^5). The calculation is performed in the limit of large center of mass energies squared s≫me2s \gg m_e^2. These terms supplement the known corrections to O(α2)O(\alpha^2), which were completed recently. Given the high precision at future colliders operating at very large luminosity, these corrections are important for concise theoretical predictions. The present calculation needs the calculation of one more two--loop massive operator matrix element in QED. The radiators are obtained as solutions of the associated Callen--Symanzik equations in the massive case. The radiators can be expressed in terms of harmonic polylogarithms to weight {\sf w = 6} of argument zz and (1−z)(1-z) and in Mellin NN space by generalized harmonic sums. Numerical results are presented on the position of the ZZ peak and corrections to the ZZ width, ΓZ\Gamma_Z. The corrections calculated result into a final theoretical accuracy for δMZ\delta M_Z and δΓZ\delta \Gamma_Z which is estimated to be of O(30 keV) at an anticipated systematic accuracy at the FCC\_ee of \sim 100 keV. This precision cannot be reached, however, by including only the corrections up to O(α3)O(\alpha^3).Comment: 58 pages, 3 Figure

    Continuous matter creation and the acceleration of the universe: the growth of density fluctuations

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    Cosmologies including continuous matter creation are able to reproduce the main properties of the standard Λ\LambdaCDM model, in particular in cases where the particle and entropy production rates are equal. These specific models, characterized by a mass density equal to the critical value, behave like the standard Λ\LambdaCDM model at early times whereas their late evolution is similar to the steady-state cosmology. The maximum amplitude of density fluctuations in these models depends on the adopted creation rate, related here to the parameter Ωv\Omega_v and this limitation could be a difficulty for the formation of galaxies and large-scale structure in this class of universe. Additional problems are related with predictions either of the random peculiar velocities of galaxies or the present density of massive clusters of galaxies, both being largely overestimated with respect to observational data.Comment: 11 pages, 2 figures, accepted for publication in General Relativity and Gravitatio

    Dynamics of a superconducting qubit coupled to the quantized cavity field: a unitary transformation approach

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    We present a novel approach for studying the dynamics of a superconducting qubit in a cavity. We succeed in linearizing the Hamiltonian through the application of an appropriate unitary transformation followed by a rotating wave approximation (RWA). For certain values of the parameters involved, we show that it is possible to obtain a a Jaynes-Cummings type Hamiltonian. As an example, we show the existence of super-revivals for the qubit inversion
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