7,842 research outputs found

    Pion spectra in Ar+Sc interactions at SPS energies

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    This contribution discusses recent results from analysis of Ar+Sc interactions recorded with the NA61/SHINE detector at six beam momenta: 13A, 19A, 30A, 40A, 75A, 150A GeV/c at the CERN SPS. Rapidity and transverse mass spectra of pions obtained with the "h-" analysis method are presented and compared to results from p+p, Be+Be and Pb+Pb collisions.Comment: Presented at the Critical Point and Onset of Deconfinement 2016, Wroclaw, Poland, May 30th - June 4th, 201

    Identified kaon production in Ar+Sc collisions at SPS energies

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    NA61/SHINE is a fixed target experiment at the CERN Super Proton Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this talk, the newest preliminary results on kaon spectra produced in Ar+Sc collisions at three beam momenta (30A, 40A and 75A) will be shown. The distributions of transverse mass and rapidity will be compared with results of NA61/SHINE (p+p, Be+Be) and NA49 (Pb+Pb, C+C, Si+Si), as well as with available world data

    Transmission research activities at NASA Lewis Research Center

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    A joint research program, to advance the technology of rotorcraft transmissions, consists of analytical and experimental efforts to achieve the overall goals of reducing transmission weight and noise, while increasing life and reliability. Recent activities in the areas of transmission and related component research are highlighted. Current areas include specific technologies in support of military rotary wing aviation, gearing technology, transmission noise reduction studies, a recent interest in gearbox diagnostics, and advanced transmission system studies. Results of recent activities are presented along with near term research plans

    Bernstein's Lethargy Theorem in Frechet Spaces

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    In this paper we consider Bernstein's Lethargy Theorem (BLT) in the context of Fr\'{e}chet spaces. Let XX be an infinite-dimensional Fr\'echet space and let V={Vn}\mathcal{V}=\{V_n\} be a nested sequence of subspaces of X X such that VnˉVn+1 \bar{V_n} \subseteq V_{n+1} for any nN n \in \mathbb{N} and X=n=1Vnˉ. X=\bar{\bigcup_{n=1}^{\infty}V_n}. Let en e_n be a decreasing sequence of positive numbers tending to 0. Under an additional natural condition on \sup\{\{dist}(x, V_n)\}, we prove that there exists xX x \in X and noN n_o \in \mathbb{N} such that \frac{e_n}{3} \leq \{dist}(x,V_n) \leq 3 e_n for any nno n \geq n_o. By using the above theorem, we prove both Shapiro's \cite{Sha} and Tyuremskikh's \cite{Tyu} theorems for Fr\'{e}chet spaces. Considering rapidly decreasing sequences, other versions of the BLT theorem in Fr\'{e}chet spaces will be discussed. We also give a theorem improving Konyagin's \cite{Kon} result for Banach spaces.Comment: 20 page

    Thermomagnetic recording and magneto-optic playback system having constant intensity laser beam control

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    A system is developed for maintaining the intensity of a laser beam at a constant level in a thermomagnetic recording and magneto-optic playback system in which an isotropic film is heated along a continuous path by the laser beam for recording. As each successive area of the path is heated locally to the vicinity of its Curie point in the presence of a controlled magnetic field, a magneto-optic density is produced proportional to the amplitude of the controlled magnetic field. To play back the recorded signal, the intensity of the laser beam is reduced and a Faraday or Kerr effect analyzer is used, with a photodetector, as a transducer for producing an output signal

    Higher-order scalar interactions and SM vacuum stability

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    Investigation of the structure of the Standard Model effective potential at very large field strengths opens a window towards new phenomena and can reveal properties of the UV completion of the SM. The map of the lifetimes of the vacua of the SM enhanced by nonrenormalizable scalar couplings has been compiled to show how new interactions modify stability of the electroweak vacuum. Whereas it is possible to stabilize the SM by adding Planck scale suppressed interactions and taking into account running of the new couplings, the generic effect is shortening the lifetime and hence further destabilisation of the SM electroweak vacuum. These findings have been illustrated with phase diagrams of modified SM-like models. It has been demonstrated that stabilisation can be achieved by lowering the suppression scale of higher order operators while picking up such combinations of new couplings, which do not deepen the new minima of the potential. Our results show the dependence of the lifetime of the electroweak minimum on the magnitude of the new couplings, including cases with very small couplings (which means very large effective suppression scale) and couplings vastly different in magnitude (which corresponds to two different suppression scales).Comment: plain Latex, 9 figure

    Gauge fixing and renormalisation scale independence of tunneling rate in abelian Higgs model and in the Standard Model

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    We explicitly show perturbative gauge fixing independence of the tunneling rate to a stable radiatively induced vacuum in the abelian Higgs model. We work with a class of RξR_\xi gauges in the presence of both dimensionless and dimensionful gauge fixing parameters. We show that Nielsen identities survive the inclusion of higher order oparators and compute the tunnelling rate to the vacua modified by the nonrenormalisable operators in a gauge invariant manner. We also discuss implications of this method for the complete Standard Model

    Hints of BSM physics in the SM effective potential

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    Investigation of the structure of the Standard Model effective potential at very large field strengths opens a window towards new phenomena and can reveal properties of the UV completion of the SM. The map of the lifetimes of the vacua of the SM enhanced by nonrenormalizable scalar couplings has been compiled to show how new interactions modify stability of the electroweak vacuum. Whereas it is possible to stabilize the SM by adding Planck scale suppressed interactions and taking into account running of the new couplings, the generic effect is shortening the lifetime and hence further destabilisation of the SM electroweak vacuum. Absolute stability can be achieved by lowering the suppression scale of higher order operators while picking up such combinations of new couplings, which do not generate new deep minima in the potential. We discuss the issue of gauge dependence of the perturbative determination of the tunnelling rate and show how this rate can be made gauge independent at the leading nontrivial order of the RGE improved effective action.Comment: Proceedings of the Corfu Summer Institute 2014 "School and Workshops on Elementary Particle Physics and Gravity", 3-21 September 2014 Corfu, Greec
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