37,401 research outputs found

    Particle-number conserving analysis for the 2-quasiparticle and high-KK multi-quasiparticle states in doubly-odd 174,176{}^{174, 176}Lu

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    Two-quasiparticle bands and low-lying excited high-KK four-, six-, and eight-quasiparticle bands in the doubly-odd 174,176{}^{174, 176}Lu are analyzed by using the cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method, in which the blocking effects are taken into account exactly. The proton and neutron Nilsson level schemes for 174,176{}^{174, 176}Lu are taken from the adjacent odd-AA Lu and Hf isotopes, which are adopted to reproduce the experimental bandhead energies of the one-quasiproton and one-quasineutron bands of these odd-AA Lu and Hf nuclei, respectively. Once the quasiparticle configurations are determined, the experimental bandhead energies and the moments of inertia of these two- and multi-quasiparticle bands are well reproduced by PNC-CSM calculations. The Coriolis mixing of the low-KK (K=∣Ω1−Ω2∣K=|\Omega_1-\Omega_2|) two-quasiparticle band of the Gallagher-Moszkowski doublet with one nucleon in the Ω=1/2\Omega = 1/2 orbital is analyzed.Comment: 8 pages, 5 figures, 2 tables, to be published at Chinese Physics

    Charmless B(s)→VVB_{(s)}\to VV Decays in Factorization-Assisted Topological-Amplitude Approach

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    Within the factorization-assisted topological-amplitude approach, we studied the 33 charmless B(s)→VVB_{(s)} \to VV decays, where VV stands for a light vector meson. According to the flavor flows, the amplitude of each process can be decomposed into 8 different topologies. In contrast to the conventional flavor diagrammatic approach, we further factorize each topological amplitude into decay constant, form factors and unknown universal parameters. By χ2\chi^2 fitting 46 experimental observables, we extracted 10 theoretical parameters with χ2\chi^2 per degree of freedom around 2. Using the fitted parameters, we calculated the branching fractions, polarization fractions, CP asymmetries and relative phases between polarization amplitudes of each decay mode. The decay channels dominated by tree diagram have large branching fractions and large longitudinal polarization fraction. The branching fractions and longitudinal polarization fractions of color-suppressed decays become smaller. Current experimental data of large transverse polarization fractions in the penguin dominant decay channels can be explained by only one transverse amplitude of penguin annihilation diagram. Our predictions of those not yet measured channels can be tested in the ongoing LHCb experiment and the Belle-II experiment in future.Comment: 22 pages, 2 figure

    Optimal Posted Prices for Online Cloud Resource Allocation

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    We study online resource allocation in a cloud computing platform, through a posted pricing mechanism: The cloud provider publishes a unit price for each resource type, which may vary over time; upon arrival at the cloud system, a cloud user either takes the current prices, renting resources to execute its job, or refuses the prices without running its job there. We design pricing functions based on the current resource utilization ratios, in a wide array of demand-supply relationships and resource occupation durations, and prove worst-case competitive ratios of the pricing functions in terms of social welfare. In the basic case of a single-type, non-recycled resource (i.e., allocated resources are not later released for reuse), we prove that our pricing function design is optimal, in that any other pricing function can only lead to a worse competitive ratio. Insights obtained from the basic cases are then used to generalize the pricing functions to more realistic cloud systems with multiple types of resources, where a job occupies allocated resources for a number of time slots till completion, upon which time the resources are returned back to the cloud resource pool
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