3,722 research outputs found

    Implications of new data in charmless B decays

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    Based on the latest experimental data of B→ππB \to \pi\pi and πK\pi K modes, a model-independent analytical analysis is presented. The CP-averaged branching ratio difference ΔR=Rc−Rn\Delta R = R_c - R_n in B→πKB\to \pi K decays with Rc=2Br(π0K−)/Br(π−Kˉ0)R_c = 2Br(\pi^0K^-)/Br(\pi^-\bar{K}^0) and Rn=Br(π+K−)/2Br(π0Kˉ0)R_n =Br(\pi^+K^-)/2Br(\pi^0\bar{K}^0) is reduced though it remains larger than the prediction from the standard model(SM) as both measured RnR_n and RcR_c are enhanced, which indicates that a room for new physics becomes smaller. The present data of ππ\pi\pi decay reduce the ratio ∣C/T∣|C/T| from the previous value of ∣C/T∣≃0.8|C/T|\simeq 0.8 to ∣C/T∣≃0.65|C/T| \simeq 0.65, which is still larger than the theoretical estimations based on QCD factorization and pQCD. Within SM and flavor SU(3) symmetry, the current πK\pi K data also diminish the ratio ∣C′/T′∣|C'/T'| from the previous value ∣C′/T′∣≃2|C'/T'| \simeq 2 to ∣C′/T′∣≃1.16|C'/T'| \simeq 1.16 with a large strong phase δC′≃−2.65\delta_{C'} \simeq -2.65, while its value remains much larger than the one extracted from the ππ\pi \pi modes. The direct CP violation ACP(π0Kˉ0)A_{CP}(\pi^0\bar{K}^0) is predicted to be ACP(π0Kˉ0)=−0.15±0.03A_{CP}(\pi^0\bar{K}^0) = -0.15\pm0.03, which is consistent with the present data. Two kinds of new effects in both strong and weak phases of the electroweak penguin diagram are considered. It is found that both cases can reduce the ratio to ∣C′/T′∣=0.40∼0.80|C'/T'| = 0.40\sim 0.80 and lead to roughly the same predictions for CP violation in π0K0\pi^0 K^0.Comment: 13 pages, 4 figure

    Terrorism- a game theoretic approach

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    Terrorism which has been on the increase in recent years is of much concern to both Governments and the private sectors .This research aims at reflecting the contemporary trends in international terrorism, and suggesting the possibility of their application for the Ghanaian private sector. Game Theory, which in recent years has been increasingly used in researches and in creating anti-terrorism strategies is the method of presentation of this write-up. Game Theory is rationally used to examine this phenomenon, and with the aid of economic instruments offer new remedies

    Randomized progressive iterative approximation for B-spline curve and surface fittings

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    For large-scale data fitting, the least-squares progressive iterative approximation is a widely used method in many applied domains because of its intuitive geometric meaning and efficiency. In this work, we present a randomized progressive iterative approximation (RPIA) for the B-spline curve and surface fittings. In each iteration, RPIA locally adjusts the control points according to a random criterion of index selections. The difference for each control point is computed concerning the randomized block coordinate descent method. From geometric and algebraic aspects, the illustrations of RPIA are provided. We prove that RPIA constructs a series of fitting curves (resp., surfaces), whose limit curve (resp., surface) can converge in expectation to the least-squares fitting result of the given data points. Numerical experiments are given to confirm our results and show the benefits of RPIA

    Exclusive B→PVB \to PV Decays and CP Violation in the General two-Higgs-doublet Model

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    We calculate all the branching ratios and direct CP violations of B→PVB \to PV decays in a most general two-Higgs-doublet model with spontaneous CP violation. As the model has rich CP-violating sources, it is shown that the new physics effects to direct CP violations and branching ratios in some channels can be significant when adopting the generalized factorization approach to evaluate the hadronic matrix elements, which provides good signals for probing new physics beyond the SM in the future B experiments.Comment: 21 page

    Reconfigurable Battery Techniques and Systems: A Survey

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    Battery packs with a large number of battery cells are becoming more and more widely adopted in electronic systems, such as robotics, renewable energy systems, energy storage in smart grids, and electronic vehicles. Therefore, a well-designed battery pack is essential for battery applications. In the literature, the majority of research in battery pack design focuses on battery management system, safety circuit, and cell-balancing strategies. Recently, the reconfigurable battery pack design has gained increasing attentions as a promising solution to solve the problems existing in the conventional battery packs and associated battery management systems, such as low energy efficiency, short pack lifespan, safety issues, and low reliability. One of the most prominent features of reconfigurable battery packs is that the battery cell topology can be dynamically reconfigured in the real-time fashion based on the current condition (in terms of the state of charge and the state of health) of battery cells. So far, there are several reconfigurable battery schemes having been proposed and validated in the literature, all sharing the advantage of cell topology reconfiguration that ensures balanced cell states during charging and discharging, meanwhile providing strong fault tolerance ability. This survey is undertaken with the intent of identifying the state-of-the-art technologies of reconfigurable battery as well as providing review on related technologies and insight on future research in this emerging area

    On the Polyak momentum variants of the greedy deterministic single and multiple row-action methods

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    For solving a consistent system of linear equations, the classical row-action (also known as Kaczmarz) method is a simple while really effective iteration solver. Based on the greedy index selection strategy and Polyak's heavy-ball momentum acceleration technique, we propose two deterministic row-action methods and establish the corresponding convergence theory. We show that our algorithm can linearly converge to a least-squares solution with minimum Euclidean norm. Several numerical studies have been presented to corroborate our theoretical findings. Real-world applications, such as data fitting in computer-aided geometry design, are also presented for illustrative purposes

    ICPR2017 – The Fourth International Conference on Practice Research: overview

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    This paper reports issues arising from the Fourth International Conference on Practice Research, held in Hong Kong in May 2017. The issues were identified by specially convened group of conference participants, and include the need to develop a better language to describe practice research in terms that make sense to practitioners, improved support for practitioners to conduct research, recognising the different drivers for practice research in different countries, and enhancing practitioners' coordinating and leadership roles

    On the extended randomized multiple row method for solving linear least-squares problems

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    The randomized row method is a popular representative of the iterative algorithm because of its efficiency in solving the overdetermined and consistent systems of linear equations. In this paper, we present an extended randomized multiple row method to solve a given overdetermined and inconsistent linear system and analyze its computational complexities at each iteration. We prove that the proposed method can linearly converge in the mean square to the least-squares solution with a minimum Euclidean norm. Several numerical studies are presented to corroborate our theoretical findings. The real-world applications, such as image reconstruction and large noisy data fitting in computer-aided geometric design, are also presented for illustration purposes
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