4,289 research outputs found

    Tensor interactions and Ï„\tau decays

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    We study the effects of charged tensor weak currents on the strangeness-changing decays of the τ\tau lepton. First, we use the available information on the Ke3+K^+_{e3} form factors to obtain BR(τ−→K−π0ντ)∼O(10−4)(\tau^- \rightarrow K^-\pi^0 \nu_{\tau})\sim {\cal O}(10^{-4}) when the KπK\pi system is produced in an antisymmetric tensor configuration. Then, we propose a mechanism for the direct production of the K2∗(1430)K_2^*(1430) in τ\tau decays. Using the current upper limit on this decay we set a bound on the symmetric tensor interactions.Comment: 13 pages, Late

    Solvability of the Dirichlet, Neumann and the regularity problems for parabolic equations with H\"older continuous coefficients

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    We establish the L2L^2-solvability of Dirichlet, Neumann and regularity problems for divergence-form heat (or diffusion) equations with H\"older-continuous diffusion coefficients, on bounded Lipschitz domains in Rn\mathbb{R}^n. This is achieved through the demonstration of invertibility of the relevant layer-potentials which is in turn based on Fredholm theory and a new systematic approach which yields suitable parabolic Rellich-type estimates

    Transference of local to global L2L^2 maximal estimates for dispersive partial differential equations

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    In this paper we give an elementary proof for transference of local to global maximal estimates for dispersive PDEs. This is done by transferring local L2L^2 estimates for certain oscillatory integrals with rough phase functions, to the corresponding global estimates. The elementary feature of our approach is that it entirely avoids the use of the wave packet techniques which are quite common in this context, and instead is based on scalings and classical oscillatory integral estimates.Comment: 10 page

    One-Loop Electroweak Corrections to the Muon Anomalous Magnetic Moment Using the Pinch Technique

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    The definition of the physical properties of particles in perturbative gauge theories must satisfy gauge invariance as a requisite. The Pinch Technique provides a framework to define the electromagnetic form factors and the electromagnetic static properties of fundamental particles in a consistent and gauge-invariant form. We apply a simple prescription derived in this formalism to check the calculation of the gauge-invariant one-loop bosonic electroweak corrections to the muon anomalous magnetic moment.Comment: 6 pages and 1 eps figur

    Modeling non-thermal emission from stellar bow shocks

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    Runaway O- and early B-type stars passing throughout the interstellar medium at supersonic velocities and characterized by strong stellar winds may produce bow shocks that can serve as particle acceleration sites. Previous theoretical models predict the production of high energy photons by non-thermal radiative processes, but their efficiency is still debated. We aim to test and explain the possibility of emission from the bow shocks formed by runaway stars traveling through the interstellar medium by using previous theoretical models. We apply our model to AE Aurigae, the first reported star with an X-ray detected bow shock, to BD+43 3654, in which the observations failed in detecting high energy emission, and to the transition phase of a supergiant star in the late stages of its life.From our analysis, we confirm that the X-ray emission from the bow shock produced by AE Aurigae can be explained by inverse Compton processes involving the infrared photons of the heated dust. We also predict low high energy flux emission from the bow shock produced by BD+43 3654, and the possibility of high energy emission from the bow shock formed by a supergiant star during the transition phase from blue to red supergiant.Bow shock formed by different type of runaway stars are revealed as a new possible source of high energy photons in our neighbourhood

    Determination of the Higgs boson mass by the cancellation of ultraviolet divergencies in the SU(2)L×U(1)YSU(2)_L\times U(1)_Y Theory

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    We assume the vanishing of the quadratic divergences in the SU(2)L⊗U(1)SU(2)_L \otimes U(1) electroweak theory. Using  \, the  \, top  \, mass  \, value reported recently by the CDF Collaboration mt=176±8±10GeVm_t = 176 \pm 8 \pm 10 GeV, we predict the mass of the Higgs boson to be mH=321±29GeVm_H = 321 \pm 29 GeV. If we assume the vanishing of both quadratic and logarithmic divergencies of the top self-mass, we predict mt=170.5±0.3GeVm_t = 170.5 \pm 0.3 GeV and mH=308.6±0.7GeV.m_H = 308.6 \pm 0.7 GeV.Comment: Latex file, 4 page

    Tensor mesons produced in tau lepton decays

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    Light tensor mesons (T = a_2, f_2 and K_2^*) can be produced in decays of tau leptons. In this paper we compute the branching ratios of tau --> T pi nu decays by assuming the dominance of intermediate virtual states to model the form factors involved in the relevant hadronic matrix element. The exclusive f_2(1270) pi^- decay mode turns out to have the largest branching ratio, of O(10^-4) . Our results indicate that the contributions of tensor meson intermediate states to the three-pseudoscalar channels of tau decays are rather small.Comment: 10 pages, 1 figure. Version accepted for publication in PRD, some typos are corrected and comments are added in section 4. Conclusions remain unchange

    An approach to emotion recognition in single-channel EEG signals: a mother child interaction

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    In this work, we perform a first approach to emotion recognition from EEG single channel signals extracted in four (4) mother-child dyads experiment in developmental psychology -- Single channel EEG signals are analyzed and processed using several window sizes by performing a statistical analysis over features in the time and frequency domains -- Finally, a neural network obtained an average accuracy rate of 99% of classification in two emotional states such as happiness and sadness20th Argentinean Bioengineering Society Congress, SABI 2015 (XX Congreso Argentino de Bioingeniería y IX Jornadas de Ingeniería Clínica)28–30 October 2015, San Nicolás de los Arroyos, Argentin
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