378 research outputs found

    Development and Dissemination of a New Multidisciplinary Undergraduate Curriculum in Digital Forensics

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    The Information Trust Institute (ITI) at the University of Illinois at Urbana-Champaign is developing an entirely new multidisciplinary undergraduate curriculum on the topic of digital forensics, and this paper presents the findings of the development process, including initial results and evaluation of a pilot offering of the coursework to students. The curriculum consists of a four-course sequence, including introductory and advanced lecture courses with parallel laboratory courses, followed by an advanced course. The content has been designed to reflect both the emerging national standards and the strong multidisciplinary character of the profession of digital forensics, and includes modules developed collaboratively by faculty experts in multiple fields of computer science, law, psychology, social sciences, and accountancy. A preliminary plan for the introductory course was presented to a workshop of digital forensics experts in May 2013 and received their strong approval. Pilot versions of the introductory and introductory lab courses were taught to a mixture of computer science and law students at the University of Illinois in the fall of 2013, and were very positively received by the students, who made it clear that they appreciated the multidisciplinary approach. The curriculum, which is designed to obviate the need for expensive labs or team-teaching by specialized faculty, will be made available to other colleges and universities in order to improve the content and quality of existing digital forensics programs, to inspire and greatly facilitate the creation of new programs, and, ultimately, to increase the number of educated practitioners. The developed resources can be used as the basis for future academic programs, distance learning, and multidisciplinary, multi-institutional programs that meet evolving digital forensics educational standards. Much of the material, including a virtual laboratory, will be provided on-line. Introductory course materials will be distributed to other institutions beginning in the summer of 2014; advanced course materials should be available for distribution in 2015. Related outreach activities have been undertaken and will be continued. Keywords: Digital forensics, Computer forensics, Curriculum development, Curriculum standards, Education standards, Training standards, Undergraduate education, Interdisciplinary studie

    Correction Factors for Reactions involving Quark-Antiquark Annihilation or Production

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    In reactions with qqˉq \bar q production or qqˉq\bar q annihilation, initial- and final-state interactions give rise to large corrections to the lowest-order cross sections. We evaluate the correction factor first for low relative kinetic energies by studying the distortion of the relative wave function. We then follow the procedure of Schwinger to interpolate this result with the well-known perturbative QCD vertex correction factors at high energies, to obtain an explicit semi-empirical correction factor applicable to the whole range of energies. The correction factor predicts an enhancement for qqˉq\bar q in color-singlet states and a suppression for color-octet states, the effect increasing as the relative velocity decreases. Consequences on dilepton production in the quark-gluon plasma, the Drell-Yan process, and heavy quark production processes are discussed.Comment: 25 pages (REVTeX), includes 2 uuencoded compressed postscript figure

    QCD Radiative Corrections to the Leptonic Decay Rate of the B_c Meson

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    The QCD radiative corrections to the leptonic decay rate of the BcB_c meson are calculated using the formalism of nonrelativistic QCD (NRQCD) to separate short-distance and long-distance effects. The BcB_c decay constant is factored into a sum of NRQCD matrix elements each multiplied by a short-distance coefficient. The short-distance coefficient for the leading matrix element is calculated to order αs\alpha_s by matching a perturbative calculation in full QCD with the corresponding perturbative calculation in NRQCD. This short-distance correction decreases the leptonic decay rate by approximately 15%15\%.Comment: Changed Eq. 2 to read 1/(8 \pi), put in a missing i M_{B_c} in Eq. 18, and put in a normalisation factor of 2 M_{B_c} in Eq. 19

    Random matrix theory and QCD3QCD_3

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    We suggest that the spectral properties near zero virtuality of three dimensional QCD, follow from a Hermitean random matrix model. The exact spectral density is derived for this family of random matrix models both for even and odd number of fermions. New sum rules for the inverse powers of the eigenvalues of the Dirac operator are obtained. The issue of anomalies in random matrix theories is discussed.Comment: 10p., SUNY-NTG-94/1

    Quarkonia and the Pole Mass

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    The pole mass of a heavy quark is ambiguous by an amount of order ΛQCD\Lambda_{QCD}. We show that the heavy-quark potential, V(r)V(r), is similarly ambiguous, but that the total static energy, 2Mpole+V(r)2M_{pole}+V(r), is unambiguous when expressed in terms of a short-distance mass. This implies that the extraction of a short-distance mass from the quarkonium spectrum is free of an ambiguity of order ΛQCD\Lambda_{QCD}, in contrast with the pole mass.Comment: 6 pages, LateX. Minor revisions for publicatio

    Phase-plane analysis of Friedmann-Robertson-Walker cosmologies in Brans-Dicke gravity

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    We present an autonomous phase-plane describing the evolution of Friedmann-Robertson-Walker models containing a perfect fluid (with barotropic index gamma) in Brans-Dicke gravity (with Brans-Dicke parameter omega). We find self-similar fixed points corresponding to Nariai's power-law solutions for spatially flat models and curvature-scaling solutions for curved models. At infinite values of the phase-plane variables we recover O'Hanlon and Tupper's vacuum solutions for spatially flat models and the Milne universe for negative spatial curvature. We find conditions for the existence and stability of these critical points and describe the qualitative evolution in all regions of the (omega,gamma) parameter space for 0-3/2. We show that the condition for inflation in Brans-Dicke gravity is always stronger than the general relativistic condition, gamma<2/3.Comment: 24 pages, including 9 figures, LaTe

    Stars in five dimensional Kaluza Klein gravity

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    In the five dimensional Kaluza Klein (KK) theory there is a well known class of static and electromagnetic--free KK--equations characterized by a naked singularity behavior, namely the Generalized Schwarzschild solution (GSS). We present here a set of interior solutions of five dimensional KK--equations. These equations have been numerically integrated to match the GSS in the vacuum. The solutions are candidates to describe the possible interior perfect fluid source of the exterior GSS metric and thus they can be models for stars for static, neutral astrophysical objects in the ordinary (four dimensional) spacetime.Comment: 15 pages, 8 figures. To be published in EPJ

    Qualitative properties of scalar-tensor theories of Gravity

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    The qualitative properties of spatially homogeneous stiff perfect fluid and minimally coupled massless scalar field models within general relativity are discussed. Consequently, by exploiting the formal equivalence under conformal transformations and field redefinitions of certain classes of theories of gravity, the asymptotic properties of spatially homogeneous models in a class of scalar-tensor theories of gravity that includes the Brans-Dicke theory can be determined. For example, exact solutions are presented, which are analogues of the general relativistic Jacobs stiff perfect fluid solutions and vacuum plane wave solutions, which act as past and future attractors in the class of spatially homogeneous models in Brans-Dicke theory.Comment: 19 page

    Neutron Star Constraints on the H Dibaryon

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    We study the influence of a possible H dibaryon condensate on the equation of state and the overall properties of neutron stars whose population otherwise contains nucleons and hyperons. In particular, we are interested in the question of whether neutron stars and their masses can be used to say anything about the existence and properties of the H dibaryon. We find that the equation of state is softened by the appearance of a dibaryon condensate and can result in a mass plateau for neutron stars. If the limiting neutron star mass is about that of the Hulse-Taylor pulsar a condensate of H dibaryons of vacuum mass 2.2 GeV and a moderately attractive potential in the medium could not be ruled out. On the other hand, if the medium potential were even moderately repulsive, the H, would not likely exist in neutron stars. If neutron stars of about 1.6 solar mass were known to exist, attractive medium effects for the H could be ruled out. Certain ranges of dibaryon mass and potential can be excluded by the mass of the Hulse-Taylor pulsar which we illustrate graphically.Comment: Revised by the addition of a figure showing the region of dibaryon mass and potential excluded by the Hulse-Taylor pulsar. 18 pages, 11 figures, latex (submitted to Phys. Rev. C

    Ratio of Hadronic Decay Rates of J\psi and \psi(2S) and the \rho\pi Puzzle

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    The so-called \rho\pi puzzle of J\psi and \psi(2S) decays is examined using the experimental data available to date. Two different approaches were taken to estimate the ratio of J\psi and \psi(2S) hadronic decay rates. While one of the estimates could not yield the exact ratio of \psi(2S) to J\psi inclusive hadronic decay rates, the other, based on a computation of the inclusive ggg decay rate for \psi(2S) (J\psi) by subtracting other decay rates from the total decay rate, differs by two standard deviations from the naive prediction of perturbative QCD, even though its central value is nearly twice as large as what was naively expected. A comparison between this ratio, upon making corrections for specific exclusive two-body decay modes, and the corresponding experimental data confirms the puzzles in J\psi and \psi(2S) decays. We find from our analysis that the exclusively reconstructed hadronic decays of the \psi(2S) account for only a small fraction of its total decays, and a ratio exceeding the above estimate should be expected to occur for a considerable number of the remaining decay channels. We also show that the recent new results from the BES experiment provide crucial tests of various theoretical models proposed to explain the puzzle.Comment: 8 pages, no figure, 4 table
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