14,454 research outputs found

    Comments on "Observation of Long-Range, Near-Side Angular Correlations in proton-proton Collisions at the LHC" by CMS Collaboration. arXiv:1009.4122[hep-ex]

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    We present comments on the paper "Observation of Long-Range, Near-Side Angular Correlations in proton-proton Collisions at the LHC"

    Applications of concurrent access patterns in web usage mining

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    This paper builds on the original data mining and modelling research which has proposed the discovery of novel structural relation patterns, applying the approach in web usage mining. The focus of attention here is on concurrent access patterns (CAP), where an overarching framework illuminates the methodology for web access patterns post-processing. Data pre-processing, pattern discovery and patterns analysis all proceed in association with access patterns mining, CAP mining and CAP modelling. Pruning and selection of access pat-terns takes place as necessary, allowing further CAP mining and modelling to be pursued in the search for the most interesting concurrent access patterns. It is shown that higher level CAPs can be modelled in a way which brings greater structure to bear on the process of knowledge discovery. Experiments with real-world datasets highlight the applicability of the approach in web navigation

    Shell model description of Ge isotopes

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    A shell model study of the low energy region of the spectra in Ge isotopes for 38≀N≀5038\leq N\leq 50 is presented, analyzing the excitation energies, quadrupole moments, B(E2)B(E2) values and occupation numbers. The theoretical results have been compared with the available experimental data. The shell model calculations have been performed employing three different effective interactions and valence spaces.We have used two effective shell model interactions, JUN45 and jj44b, for the valence space f5/2 p g9/2f_{5/2} \, p \,g_{9/2} without truncation. To include the proton subshell f7/2f_{7/2} in valence space we have employed the fpgfpg effective interaction due to Sorlin {\it et al.}, with 48^{48}Ca as a core and a truncation in the number of excited particles.Comment: 10 pages, 10 figures, Proc. of the XXXV Nuclear Physics Symposium, January 3-6 2012, Cocoyoc, Morelos, Mexico. IOP Journal of Physics: Conference Series (in press

    Probing Gauge String Formation in a Superconducting Phase Transition

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    Superconductors are the only experimentally accessible systems with spontaneously broken gauge symmetries which support topologically nontrivial defects, namely string defects. We propose two experiments whose aim is the observation of the dense network of these strings thought to arise, via the Kibble mechanism, in the course of a spontaneous symmetry breaking phase transition. We suggest ways to estimate the order of magnitude of the density of flux tubes produced in the phase transition. This may provide an experimental check for the theories of the production of topological defects in a spontaneously broken gauge theory, such as those employed in the context of the early Universe.Comment: 16 pages (Latex), 4 figures included, change in title, some minor changes, published versio

    Formation of Topological Defects with Explicit Symmetry Breaking

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    We demonstrate a novel mechanism for the formation of topological defects in a first order phase transition for theories in the presence of small explicit symmetry breaking terms. We carry out numerical simulations of collisions of two bubbles in 2+1 dimensions for a field theory where U(1) global symmetry is spontaneously as well as explicitly broken. In the coalesced region of bubble walls, field oscillations result in the decay of the coalesced portion in a large number of defects (e.g. ten vortices and anti-vortices). We discuss the implications of our results for axionic strings in the early Universe, for baryon formation in quark-gluon plasma, and for electric or magnetic field.Comment: Latex file, 8 pages, 6 uuencoded postscript figure

    The extent of strangeness in equilibration in quark-gluon plasma

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    The evolution and production of strangeness from chemically equilibrating and transversely expanding quark gluon plasma which may be formed in the wake of relativistic heavy ion collisions is studied with initial conditions obtained from the Self Screened Parton Cascade (SSPC) model. The extent of partonic equilibration increases almost linearly with the square of the initial energy density, which can then be scaled with number of participants.Comment: 4 pages including three figures, talk given at ICPAQGP'01, Jaipur, India, to appear in Pramana - Journal of Physics, Indian Academy of Scienc

    Cosmic Evolution with Early and Late Acceleration Inspired by Dual Nature of the Ricci Scalar Curvature

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    In the present paper, it is found that dark energy emerges spontaneously from the modified gravity. According to cosmological scenario, obtained here, the universe inflates for ∌10−37\sim 10^{-37} sec. in the beginning and late universe accelerates after 8.58 Gyrs. During the long intermediate period, it decelerates driven by radiation and subsequently by matter. Emerged gravitational dark energy mimics quintessence and its density falls by 115 orders from its initial value 2.58×1068GeV42.58\times 10^{68} {\rm GeV}^4 to its current value 2.19×10−47GeV42.19\times 10^{-47} {\rm GeV}^4 .Comment: 40 pages. To appearin Int. J. Mod. Phys.
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