1,834 research outputs found

    Design and development of a fast scan infrared detection and measurement instrument

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    Infrared microscope instrument measures and plots the infrared profile of semiconductor chips, transistors and integrated circuits. Infrared analyses yields information on electrical and physical properties, enabling manufacturing improvements in semiconductor performance and reliability. Operational performance and main sections of the instrument are given

    γγ\gamma \gamma Processes at High Energy pp Colliders

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    In this note we investigate the production of charged heavy particles via \gaga\ fusion at high energy pp colliders. We revise previous claims that the \gaga\ cross section is comparable to or larger than that for the corresponding Drell-Yan process at high energies. Indeed we find that the \gaga\ contribution to the total production cross section at pp is far below the Drell-Yan cross section. As far as the individual elastic, semi-elastic and inelastic contributions to the \gaga\ process are concerned we find that they are all of the same order of magnitude.Comment: REVTEX, 12 pages, two uuencoded figures appended at the end of the fil

    A game of cops and robbers played on products of graphs

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    The game of cops and robbers is played with a set of 'cops' and a 'robber' who occupy some vertices of a graph. Both sides have perfect information and they move alternately to adjacent vertices. The robber is captured if at least one of the cops occupies the same vertex as the robber. The problem is to determine on a given graph, G, the least number of cops sufficient to capture the robber, called the cop-number, c(G). We investigate this game on three products of graphs: the Cartesian, categorical, and strong products

    CP-Violation in Bosonic Sector of SM with two Higgs Doublets

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    We investigate CP-violation effects in the bosonic sector of the Standard Model (SM) with two Higgs doublets. First we calculate the mass eigenstates of the physical neutral Higgses for small but nonzero CP-violation parameter ξ\xi_{\ast}, and then a ``forward-backward'' asymmetry Afb{\cal A}_{fb} for the decay HW+WZH \to W^+W^-Z that would be a signal of CP-violation. Although the effects are in general small (Afb=Γfb/ΓO(103){\cal A}_{fb} = \Gamma_{fb}/\Gamma \sim {\cal O}(10^{-3})), Afb{\cal A}_{fb} turns out to be a rather clean signal of CP-violation, since neither the CP-conserving final state interactions nor the direct production background events contribute to Γfb\Gamma_{fb}. The process is a counterexample to the widespread belief that CP-violation processes must involve fermions. The CKM-type CP-violation effects that could in principle also contribute to Afb{\cal A}_{fb} are negligible. The nonzero Afb{\cal A}_{fb} could possibly be detected at some later stage in future colliders such as LHC or SSC.Comment: 11 pages (standard LaTeX), 3 figures (available from the author), DO-TH 93-1

    No classical limit of quantum decay for broad states

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    Though the classical treatment of spontaneous decay leads to an exponential decay law, it is well known that this is an approximation of the quantum mechanical result which is a non-exponential at very small and large times for narrow states. The non exponential nature at large times is however hard to establish from experiments. A method to recover the time evolution of unstable states from a parametrization of the amplitude fitted to data is presented. We apply the method to a realistic example of a very broad state, the sigma meson and reveal that an exponential decay is not a valid approximation at any time for this state. This example derived from experiment, shows the unique nature of broad resonances

    Exact Solution of the Discrete (1+1)-dimensional RSOS Model with Field and Surface Interactions

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    We present the solution of a linear Restricted Solid--on--Solid (RSOS) model in a field. Aside from the origins of this model in the context of describing the phase boundary in a magnet, interest also comes from more recent work on the steady state of non-equilibrium models of molecular motors. While similar to a previously solved (non-restricted) SOS model in its physical behaviour, mathematically the solution is more complex. Involving basic hypergeometric functions 3ϕ2{}_3\phi_2, it introduces a new form of solution to the lexicon of directed lattice path generating functions.Comment: 10 pages, 2 figure

    Effects due to a scalar coupling on the particle-antiparticle production in the Duffin-Kemmer-Petiau theory

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    The Duffin-Kemmer-Petiau formalism with vector and scalar potentials is used to point out a few misconceptions diffused in the literature. It is explicitly shown that the scalar coupling makes the DKP formalism not equivalent to the Klein-Gordon formalism or to the Proca formalism, and that the spin-1 sector of the DKP theory looks formally like the spin-0 sector. With proper boundary conditions, scattering of massive bosons in an arbitrary mixed vector-scalar square step potential is explored in a simple way and effects due to the scalar coupling on the particle-antiparticle production and localization of bosons are analyzed in some detail

    Electromagnetic properties of neutrinos

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    A short review on electromagnetic properties of neutrinos is presented. In spite of many efforts in the theoretical and experimental studies of neutrino electromagnetic properties, they still remain one of the main puzzles related to neutrinos.Comment: The talk presented by A.Studenikin at the International Conference on Topics in Astroparticle and Underground Physics, Rome (Italy), July 1-5, 200

    Remark on the vectorlike nature of the electromagnetism and the electric charge quantization

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    In this work we study the structure of the electromagnetic interactions and the electric charge quantization in gauge theories of electroweak interactions based on semi-simple groups. We show that in the standard model of the electroweak interactions the structure of the electromagnetic interactions is strongly correlated to the quantization pattern of the electric charges. We examine these two questions also in all possible chiral bilepton gauge models of the electroweak interactions. In all they we can explain the vectorlike nature of the electromagnetic interactions and the electric charge quantization together demanding nonvanishing fermion masses and the anomaly cancellations.Comment: 17 pages, latex, no figure

    Integrating precision medicine through evaluation of cell of origin in treatment planning for diffuse large B-cell lymphoma

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    Precision medicine is modernizing strategies for clinical study design to help improve diagnoses guiding individualized treatment based on genetic or phenotypic characteristics that discriminate between patients with similar clinical presentations. Methodology to personalize treatment choices is being increasingly employed in clinical trials, yielding favorable correlations with improved response rates and survival. In patients with diffuse large B-cell lymphoma (DLBCL), disease characteristics and outcomes may vary widely, underscoring the importance of patient classification through identification of sensitive prognostic features. The discovery of distinct DLBCL molecular subtypes based on cell of origin (COO) is redefining the prognosis and treatment of this heterogeneous cancer. Owing to significant molecular and clinical differences between activated B-cell-like (ABC)- and germinal center B-cell-like (GCB)-DLBCL subtypes, COO identification offers opportunities to optimize treatment selection. Widespread adoption of COO classification would greatly improve treatment and prognosis; however, limitations in interlaboratory concordance between immunohistochemistry techniques, cost, and availability of gene expression profiling tools undermine universal integration in the clinical setting. With advanced methodology to determine COO in a real-world clinical setting, therapies targeted to specific subtypes are under development. The focus here is to review applications of precision medicine exemplified by COO determination in DLBCL patients
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