5,150 research outputs found

    One Dimensional nnary Density Classification Using Two Cellular Automaton Rules

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    Suppose each site on a one-dimensional chain with periodic boundary condition may take on any one of the states 0,1,...,n10,1,..., n-1, can you find out the most frequently occurring state using cellular automaton? Here, we prove that while the above density classification task cannot be resolved by a single cellular automaton, this task can be performed efficiently by applying two cellular automaton rules in succession.Comment: Revtex, 4 pages, uses amsfont

    Finding The Sign Of A Function Value By Binary Cellular Automaton

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    Given a continuous function f(x)f(x), suppose that the sign of ff only has finitely many discontinuous points in the interval [0,1][0,1]. We show how to use a sequence of one dimensional deterministic binary cellular automata to determine the sign of f(ρ)f(\rho) where ρ\rho is the (number) density of 1s in an arbitrarily given bit string of finite length provided that ff satisfies certain technical conditions.Comment: Revtex, uses amsfonts, 10 page

    Analysis of Two-Body Decays of Charmed Baryons Using the Quark-Diagram Scheme

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    We give a general formulation of the quark-diagram scheme for the nonleptonic weak decays of baryons. We apply it to all the decays of the antitriplet and sextet charmed baryons and express their decay amplitudes in terms of the quark-diagram amplitudes. We have also given parametrizations for the effects of final-state interactions. For SU(3) violation effects, we only parametrize those in the horizontal WW-loop quark diagrams whose contributions are solely due to SU(3)-violation effects. In the absence of all these effects, there are many relations among various decay modes. Some of the relations are valid even in the presence of final-state interactions when each decay amplitude in the relation contains only a single phase shift. All these relations provide useful frameworks to compare with future experiments and to find out the effects of final-state interactions and SU(3) symmetry violations.Comment: 28 pages, 20 Tables in landscape form, 4 figures. Main changes are: (i) some errors in the Tables and in the relations between the quark-diagram amplitudes of this paper and those of Ref.[10] are corrected, (ii) improvements are made in the presentation so that comparisons with previous works and what have been done to include SU(3) breaking and final-state interactions are more clearly stated; to appear in the Physical Review

    Relation Between Quantum Speed Limits And Metrics On U(n)

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    Recently, Chau [Quant. Inform. & Comp. 11, 721 (2011)] found a family of metrics and pseudo-metrics on nn-dimensional unitary operators that can be interpreted as the minimum resources (given by certain tight quantum speed limit bounds) needed to transform one unitary operator to another. This result is closely related to the weighted 1\ell^1-norm on Rn{\mathbb R}^n. Here we generalize this finding by showing that every weighted p\ell^p-norm on Rn{\mathbb R}^n with 1\le p \le \limitingp induces a metric and a pseudo-metric on nn-dimensional unitary operators with quantum information-theoretic meanings related to certain tight quantum speed limit bounds. Besides, we investigate how far the correspondence between the existence of metrics and pseudo-metrics of this type and the quantum speed limits can go.Comment: minor amendments, 6 pages, to appear in J.Phys.

    Exclusive Hadronic D Decays to eta' and eta

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    Hadronic decay modes D0(Kˉ0,Kˉ0)η,ηD^0\to(\bar K^0, \bar K^{*0})\eta,\eta' and (D+,Ds+)(π+,ρ+)η,η(D^+,D_s^+)\to(\pi^+,\rho^+)\eta,\eta' are studied in the generalized factorization approach. Form factors for (D,Ds+)(η,η)(D,D_s^+)\to(\eta,\eta') transitions are carefully evaluated by taking into account the wave function normalization of the eta and eta'. The predicted branching ratios are generally in agreement with experiment except for D0Kˉ0η,D+π+ηD^0\to\bar K^0\eta', D^+\to\pi^+\eta and Ds+ρ+ηD_s^+\to\rho^+\eta'; the calculated decay rates for the first two decay modes are too small by an order of magnitude. We show that the weak decays D0Kπ+D^0\to K^-\pi^+ and D+K+Kˉ0D^+\to K^+\bar K^0 followed by resonance-induced final-state interactions (FSI), which are amenable technically, are able to enhance the branching ratios of D0Kˉ0ηD^0\to\bar K^0\eta' and D+π+ηD^+\to\pi^+\eta dramatically without affecting the agreement between theory and experiment for D0Kˉ0ηD^0\to\bar K^0\eta and D+π+ηD^+\to\pi^+\eta'. We argue that it is difficult to understand the observed large decay rates of Ds+ρ+ηD_s^+\to \rho^+\eta' and ρ+η\rho^+\eta simultaneously; FSI, W-annihilation and the production of excess eta' from gluons are not helpful in this regard. The large discrepancy between the factorization hypothesis and experiment for the ratio of Ds+ρ+ηD_s^+\to\rho^+ \eta' and Ds+ηe+νD_s^+\to\eta' e^+\nu remains as an enigma.Comment: 15 pages, 1 figure, to appear in Phys. Rev. D. Form factors for D to eta and eta' transitions are slightly change

    Flavor SU(3) symmetry and QCD factorization in BPPB \to PP and PVPV decays

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    Using flavor SU(3) symmetry, we perform a model-independent analysis of charmless Bˉu,d(Bˉs)PP, PV\bar B_{u,d} (\bar B_s) \to PP, ~PV decays. All the relevant topological diagrams, including the presumably subleading diagrams, such as the QCD- and EW-penguin exchange diagrams and flavor-singlet weak annihilation ones, are introduced. Indeed, the QCD-penguin exchange diagram turns out to be important in understanding the data for penguin-dominated decay modes. In this work we make efforts to bridge the (model-independent but less quantitative) topological diagram or flavor SU(3) approach and the (quantitative but somewhat model-dependent) QCD factorization (QCDF) approach in these decays, by explicitly showing how to translate each flavor SU(3) amplitude into the corresponding terms in the QCDF framework. After estimating each flavor SU(3) amplitude numerically using QCDF, we discuss various physical consequences, including SU(3) breaking effects and some useful SU(3) relations among decay amplitudes of BˉsPV\bar B_s \to PV and BˉdPV\bar B_d \to PV.Comment: 47 pages, 3 figures, 28 table

    Quantum Convolutional Error Correcting Codes

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    I report two general methods to construct quantum convolutional codes for NN-state quantum systems. Using these general methods, I construct a quantum convolutional code of rate 1/4, which can correct one quantum error for every eight consecutive quantum registers.Comment: Minor revisions and clarifications. To appear in Phys. Rev.

    Two-Body Cabibbo-Suppressed Charmed Meson Decays

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    Singly-Cabibbo-suppressed decays of charmed particles governed by the quark subprocesses csusˉc \to s u \bar s and cdudˉc \to d u \bar d are analyzed using a flavor-topology approach, based on a previous analysis of the Cabibbo-favored decays governed by csudˉc \to s u \bar d. Decays to PPPP and PVPV, where PP is a pseudoscalar meson and VV is a vector meson, are considered. We include processes in which η\eta and η\eta ' are produced.Comment: 18 pages, latex, 2 figures, to be submitted to Phys. Rev.

    Benefit sharing for BIM implementation: Tackling the moral hazard dilemma in inter-firm cooperation

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    Building information modeling (BIM) plays an important role in furthering value-creation of construction projects by advocating the inter-firm cooperation. When implementing BIM, however, individual firms inherently safeguard their self-interests regardless of the fact that inter-firm cooperation might reap joint BIM benefits for a project overall, which epitomizes a typical problem of moral hazards in project-based organizations. This paper develops an outcome-linked benefit sharing model that considers sharing joint BIM benefits among stakeholders including designers, contractors, and clients for tracking moral hazards therein. By modeling stakeholders' behaviors as evolutionary games within a principal–agent formalism, it has been deducted that (1) designers/contractors could be incentivized to cooperate had each stakeholder received a share higher than the quotient of BIM costs over value-creation in the design/construction phase; and (2) how joint BIM benefits can be more than noncooperation outcomes is key for clients to support BIM implementation
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