37,545 research outputs found

    Inclusive Decay Rate for BXd+γB \to X_d + \gamma in Next-to-Leading Logarithmic Order and CP Asymmetry in the Standard Model

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    We compute the decay rate for the CKM-suppressed electromagnetic penguin decay BXd+γB \to X_d + \gamma (and its charge conjugate) in NLO QCD, including leading power corrections in 1/mb21/m_b^2 and 1/mc21/m_c^2 in the standard model. The average branching ratio of the decay BXdγB \to X_d\gamma and its charge conjugate is estimated to be in the range 6.0×1062.6×1056.0 \times 10^{-6} \leq \leq 2.6 \times 10^{-5}, obtained by varying the CKM-Wolfenstein parameters ρ\rho and η\eta in the range 0.1ρ0.4-0.1 \leq \rho \leq 0.4 and 0.2η0.460.2 \leq \eta \leq 0.46 and taking into account other parametric dependence. In the stated range of the CKM parameters, we find the ratio R(dγ/sγ)=<BR(BXdγ)>/R(d\gamma/s\gamma) = <BR(B \to X_d\gamma)>/ to lie in the range between 0.017 and 0.074. Theoretical uncertainties in this ratio are found to be small. Hence, this ratio is well suited to provide independent constraints on the CKM parameters. The CP-asymmetry in the BXdγB \to X_d \gamma decay rates is found to be in the range (735)(7 - 35)%. Both the decay rates and CP asymmetry are measurable in forthcoming experiments at BB factories and possibly at HERA-B.Comment: 17 pages including 7 postscript figures; uses epsfig; The changes w.r.t the previous version are: A comment about the Bremsstrahlung corrections is added as well as a note on the feasibility of the measurement $B -> X_d gamma

    Enabling adaptive scientific workflows via trigger detection

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    Next generation architectures necessitate a shift away from traditional workflows in which the simulation state is saved at prescribed frequencies for post-processing analysis. While the need to shift to in~situ workflows has been acknowledged for some time, much of the current research is focused on static workflows, where the analysis that would have been done as a post-process is performed concurrently with the simulation at user-prescribed frequencies. Recently, research efforts are striving to enable adaptive workflows, in which the frequency, composition, and execution of computational and data manipulation steps dynamically depend on the state of the simulation. Adapting the workflow to the state of simulation in such a data-driven fashion puts extremely strict efficiency requirements on the analysis capabilities that are used to identify the transitions in the workflow. In this paper we build upon earlier work on trigger detection using sublinear techniques to drive adaptive workflows. Here we propose a methodology to detect the time when sudden heat release occurs in simulations of turbulent combustion. Our proposed method provides an alternative metric that can be used along with our former metric to increase the robustness of trigger detection. We show the effectiveness of our metric empirically for predicting heat release for two use cases.Comment: arXiv admin note: substantial text overlap with arXiv:1506.0825

    Complete gluon bremsstrahlung corrections to the process b -> s l+ l-

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    In a recent paper, we presented the calculation of the order (alpha_s) virtual corrections to b->s l+ l- and of those bremsstrahlung terms which are needed to cancel the infrared divergences. In the present paper we work out the remaining order(alpha_s) bremsstrahlung corrections to b->s l+ l- which do not suffer from infrared and collinear singularities. These new contributions turn out to be small numerically. In addition, we also investigate the impact of the definition of the charm quark mass on the numerical results.Comment: 20 pages including 11 postscript figure

    SARS and Security: Health in the 'New Normal'

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    In "SARS and Security: Health in the "New Normal,"" Claire Hooker and Harris Ali illustrate how the boundaries between public health and national security are being blurred in the present age. The authors show how the "new normal" is an ideology that constructs the world as inherently insecure. Their paper demonstrates how this ideology converges along a number of tangents with neoliberalism that has repercussions for how matters of public health and national security are being reimagined in North America. The new normal, as the authors argue, is a discursive frame that shapes how governments interpret and respond to crises in the aftermath of the 9/11 terrorist attacks and the worldwide outbreak of SARS

    SARS and Security: Health in the 'New Normal'

    Get PDF
    In "SARS and Security: Health in the "New Normal,"" Claire Hooker and Harris Ali illustrate how the boundaries between public health and national security are being blurred in the present age. The authors show how the "new normal" is an ideology that constructs the world as inherently insecure. Their paper demonstrates how this ideology converges along a number of tangents with neoliberalism that has repercussions for how matters of public health and national security are being reimagined in North America. The new normal, as the authors argue, is a discursive frame that shapes how governments interpret and respond to crises in the aftermath of the 9/11 terrorist attacks and the worldwide outbreak of SARS

    Mechanism, dynamics, and biological existence of multistability in a large class of bursting neurons

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    Multistability, the coexistence of multiple attractors in a dynamical system, is explored in bursting nerve cells. A modeling study is performed to show that a large class of bursting systems, as defined by a shared topology when represented as dynamical systems, is inherently suited to support multistability. We derive the bifurcation structure and parametric trends leading to multistability in these systems. Evidence for the existence of multirhythmic behavior in neurons of the aquatic mollusc Aplysia californica that is consistent with our proposed mechanism is presented. Although these experimental results are preliminary, they indicate that single neurons may be capable of dynamically storing information for longer time scales than typically attributed to nonsynaptic mechanisms.Comment: 24 pages, 8 figure
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