51 research outputs found

    Collective and fractal properties of pion jets in the four-velocity space at intermediate energies

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    Experimental results are presented for study of collective and fractal properties of soft pion jets in the space of relative four-dimensional velocities. Significant decreasing is obtained for mean square of second particle distances from jet axis for pion-proton interactions at initial energies 3\sim 3 GeV in comparison with hadron-nuclear collisions at close energies. The decreasing results in power dependence of distance variable on collision energy for range 24\sim 2 - 4 GeV. The observation allows us to estimate the low boundary of manifestation of color degree of freedom in pion jet production. Cluster dimension values were deduced for pion jets in various reactions. Fractional values of this dimension indicate on the manifestation of fractal-like properties by pion jets. Changing of mean kinetic energy of jet particles and fractal dimension with initial energy increasing is consistent with suggestion for presence of color degrees of freedom in pion jet production at intermediate energies.Comment: The conference "Physics of fundamental interactions". ITEP, Moscow, Russia. November 23 - 27, 200

    Autoimmune polyglandular syndrome type I. Features of clinical manifestations, difficulties in diagnosis and methods of correction

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    Autoimmune polyglandular syndrome (APG) type I is an orphan disease with autosomal recessive inheritance caused by mutations in the autoimmune regulator gene (AIRE); the disease onset typically occurs in childhood. The disease is characterized by a wide variety of clinical manifestations with a certain stage in the manifestation of individual symptoms. The rare occurrence of this pathology determines its late diagnosis, which can lead to the decompensated life-threatening conditions and an unfavorable outcome. Widely informing pediatric specialists will contribute to the development of a diagnostic algorithm for timely verifying the disease from the moment its first clinical manifestations appear, and will improve the quality and life expectancy of the patients

    Electromagnetic field and radiation for a charge moving along a helical trajectory inside a waveguide with dielectric filling

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    We investigate the electromagnetic field generated by a point charge moving along a helical trajectory inside a circular waveguide with conducting walls filled by homogeneous dielectric. The parts corresponding to the radiation field are separated and the formulae for the radiation intensity are derived for both TE and TM waves. It is shown that the main part of the radiated quanta is emitted in the form of the TE waves. Various limiting cases are considered. The results of the numerical calculations show that the insertion of the waveguide provides an additional mechanism for tuning the characteristics of the emitted radiation by choosing the parameters of the waveguide and filling medium.Comment: 17 pages, 9 figures, discussion, graphs, and references adde

    Status of Muon Collider Research and Development and Future Plans

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    The status of the research on muon colliders is discussed and plans are outlined for future theoretical and experimental studies. Besides continued work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy collider, many studies are now concentrating on a machine near 0.1 TeV (CoM) that could be a factory for the s-channel production of Higgs particles. We discuss the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from a heavy-Z target and proceeding through the phase rotation and decay (πμνμ\pi \to \mu \nu_{\mu}) channel, muon cooling, acceleration, storage in a collider ring and the collider detector. We also present theoretical and experimental R & D plans for the next several years that should lead to a better understanding of the design and feasibility issues for all of the components. This report is an update of the progress on the R & D since the Feasibility Study of Muon Colliders presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A. Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics (Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics, Accelerators and Beam

    Muon (g-2) Technical Design Report

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    The Muon (g-2) Experiment, E989 at Fermilab, will measure the muon anomalous magnetic moment a factor-of-four more precisely than was done in E821 at the Brookhaven National Laboratory AGS. The E821 result appears to be greater than the Standard-Model prediction by more than three standard deviations. When combined with expected improvement in the Standard-Model hadronic contributions, E989 should be able to determine definitively whether or not the E821 result is evidence for physics beyond the Standard Model. After a review of the physics motivation and the basic technique, which will use the muon storage ring built at BNL and now relocated to Fermilab, the design of the new experiment is presented. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2/3 approval

    Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

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    We present the first results of the Fermilab Muon g-2 Experiment for the positive muon magnetic anomaly aμ(gμ2)/2a_\mu \equiv (g_\mu-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ωa\omega_a between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω~p{\tilde{\omega}'^{}_p} in a spherical water sample at 34.7^{\circ}C. The ratio ωa/ω~p\omega_a / {\tilde{\omega}'^{}_p}, together with known fundamental constants, determines aμ(FNAL)=116592040(54)×1011a_\mu({\rm FNAL}) = 116\,592\,040(54)\times 10^{-11} (0.46\,ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ+\mu^+ and μ\mu^-, the new experimental average of aμ(Exp)=116592061(41)×1011a_\mu({\rm Exp}) = 116\,592\,061(41)\times 10^{-11} (0.35\,ppm) increases the tension between experiment and theory to 4.2 standard deviationsComment: 10 pages; 4 figure
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