1,564 research outputs found

    Production of f0(1710)f_0(1710), f0(1500)f_0(1500), and f0(1370)f_0(1370) in J/ψJ/\psi hadronic decays

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    A coherent study of the production of f0if_0^i (i=1i=1, 2, 3 corresponding to f0(1710)f_0(1710), f0(1500)f_0(1500), and f0(1370)f_0(1370)) in J/ψVf0VPPJ/\psi\to V f_0 \to V PP is reported based on a previously proposed glueball and QQˉQ\bar{Q} nonet mixing scheme, and a factorization for the decay of J/ψVf0iJ/\psi\to V f_0^i, where VV denotes the isoscalar vector mesons ϕ\phi and ω\omega, and PP denotes pseudoscalar mesons. The results show that the J/ψJ/\psi decays are very sensitive to the structure of those scalar mesons, and suggest a glueball in the 1.51.71.5-1.7 GeV region, in line with Lattice QCD. The presence of significant glueball mixings in the scalar wavefunctions produces peculiar patterns in the branching ratios for J/ψVf0iVPPJ/\psi\to V f_0^i\to VPP, which are in good agreement with the recently published experimental data from the BES collaboration.Comment: Version accepted by PRD; Numerical results in Tab IV and VI changed due to correction of an error in quoting an experimental datum; Conclusion is not change

    The Active Traveling Wave in the Cochlea

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    A sound stimulus entering the inner ear excites a deformation of the basilar membrane which travels along the cochlea towards the apex. It is well established that this wave-like disturbance is amplified by an active system. Recently, it has been proposed that the active system consists of a set of self-tuned critical oscillators which automatically operate at an oscillatory instability. Here, we show how the concepts of a traveling wave and of self-tuned critical oscillators can be combined to describe the nonlinear wave in the cochlea.Comment: 5 pages, 2 figure

    Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy

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    The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer’s disease (AD) patients using the Multiscale Entropy (MSE). The MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant difference

    Introduction to the chemistry of fractionally charged atoms: Electronegativity

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    The behavior of massive fractionally charged particles in matter is governed by the laws of chemistry if electromagnetic interactions dominate at atomic distances. Chemical properties of such "quark atoms" can be predicted by interpolating isoelectronic sequences. The properties of quark atoms lie between those of a neutral atom and an ion. Electronegativity helps in the qualitative understanding of quark chemistry. Electronegativities, together with ionization potentials and electron affinities, are computed for the quark elements. The concepts of chemical analogy and isomorphism are introduced. Analogies based on shell structure and electronegativity are established. Many quark elements cannot be compared to a single ordinary element. They are chemical chimeras. An understanding of quark chemistry is essential for the design and interpretation of quark-search experiments. The impact of chemical reactions on quark impurities in matter can be monitored by observing the behavior of more abundant isomorphic control elements. Contrary to common belief, the chemical differences between a quark element and its ordinary counterpart are substantial

    Production, Collection and Utilization of Very Long-Lived Heavy Charged Leptons

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    If a fourth generation of leptons exists, both the neutrino and its charged partner must be heavier than 45 GeV. We suppose that the neutrino is the heavier of the two, and that a global or discrete symmetry prohibits intergenerational mixing. In that case, non-renormalizable Planck scale interactions will induce a very small mixing; dimension five interactions will lead to a lifetime for the heavy charged lepton of O(1100)O(1-100) years. Production of such particles is discussed, and it is shown that a few thousands can be produced and collected at a linear collider. The possible uses of these heavy leptons is also briefly discussed.Comment: 9 pages Late

    Hadron Spectroscopy with COMPASS at CERN

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    The aim of the COMPASS hadron programme is to study the light-quark hadron spectrum, and in particular, to search for evidence of hybrids and glueballs. COMPASS is a fixed-target experiment at the CERN SPS and features a two-stage spectrometer with high momentum resolution, large acceptance, particle identification and calorimetry. A short pilot run in 2004 resulted in the observation of a spin-exotic state with JPC=1+J^{PC} = 1^{-+} consistent with the debated π1(1600)\pi1(1600). In addition, Coulomb production at low momentum transfer data provide a test of Chiral Perturbation Theory. During 2008 and 2009, a world leading data set was collected with hadron beam which is currently being analysed. The large statistics allows for a thorough decomposition of the data into partial waves. The COMPASS hadron data span over a broad range of channels and shed light on several different aspects of QCD.Comment: 4 pages, 5 figure

    BigWig and BigBed: enabling browsing of large distributed datasets

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    Summary: BigWig and BigBed files are compressed binary indexed files containing data at several resolutions that allow the high-performance display of next-generation sequencing experiment results in the UCSC Genome Browser. The visualization is implemented using a multi-layered software approach that takes advantage of specific capabilities of web-based protocols and Linux and UNIX operating systems files, R trees and various indexing and compression tricks. As a result, only the data needed to support the current browser view is transmitted rather than the entire file, enabling fast remote access to large distributed data sets

    Strangeness Content in the Nucleon

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    I review recent studies of strangeness content in the nucleon pertaining to the flavor-singlet gA0g_A^0, the sˉs\bar{s}s matrix element and the strangeness electric and magnetic form factors GEs(q2)G_E^s(q^2) and GMs(q2)G_M^s(q^2), based on lattice QCD calculations. I shall also discuss the relevance of incorporating the strangeness content in nuclei in regard to strange baryon-antibaryon productions from proton-nucleus and nucleus-nucleus collisions at SPS and RHIC energies.Comment: 11 pages, 4 figures, Invited talk at V Int. Conf. on Strangeness in Quark Matter, Berkeley, CA, July 20--25, 200
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