7,520 research outputs found

    Symmetry restoration and quantumness reestablishment

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    A realistic quantum many-body system, characterized by a generic microscopic Hamiltonian, is accessible only through approximation methods. The mean field theories, as the simplest practices of approximation methods, commonly serve as a powerful tool, but unfortunately often violate the symmetry of the Hamiltonian. The conventional BCS theory, as an excellent mean field approach, violates the particle number conservation and completely erases quantumness characterized by concurrence and quantum discord between different modes. We restore the symmetry by using the projected BCS theory and the exact numerical solution and find that the lost quantumness is synchronously reestablished. We show that while entanglement remains unchanged with the particle numbers, quantum discord behaves as an extensive quantity with respect to the system size. Surprisingly, discord is hardly dependent on the interaction strengths. The new feature of discord offers promising applications in modern quantum technologies.Comment: 17 pages and 3 figure

    Production of doubly heavy baryons via Higgs boson decays

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    We systematically analyzed the production of semi-inclusive doubly heavy baryons (Ξcc\Xi_{cc}, Ξbc\Xi_{bc} and Ξbb\Xi_{bb}) for the process H0→ΞQQ′+Q′ˉ+QˉH^0 \rightarrow \Xi_{QQ'}+ \bar {Q'} + \bar {Q} through four main Higgs decay channels within the framework of non-relativistic QCD. The contributions from the intermediate diquark states, ⟨cc⟩[1S0]6\langle cc\rangle[^{1}S_{0}]_{\mathbf{6}}, ⟨cc⟩[3S1]3ˉ\langle cc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}, ⟨bc⟩[3S1]3ˉ/6\langle bc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}/ \mathbf{6}}, ⟨bc⟩[1S0]3ˉ/6\langle bc\rangle[^{1}S_{0}]_{\mathbf{\bar 3}/ \mathbf{6}}, ⟨bb⟩[1S0]6\langle bb\rangle[^{1}S_{0}]_{\mathbf{6}} and ⟨bb⟩[3S1]3ˉ\langle bb\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}, have been taken into consideration. The differential distributions and three main sources of the theoretical uncertainties have been discussed. At the High Luminosity Large Hadron Collider, there will be about 0.43×104\times10^4 events of Ξcc\Xi_{cc}, 6.32×104\times10^4 events of Ξbc\Xi_{bc} and 0.28×104\times10^4 events of Ξbb\Xi_{bb} produced per year. There are fewer events produced at the Circular Electron Positron Collider and the International Linear Collider, about 0.26×1020.26\times 10^{2} events of Ξcc\Xi_{cc}, 3.83×1023.83\times 10^{2} events of Ξbc\Xi_{bc} and 0.17×1020.17\times 10^{2} events of Ξbb\Xi_{bb} in operation.Comment: 15 pages, 3 figures, 7 table

    The Algebraic Structure of the gl(n∣m)gl(n|m) Color Calogero-Sutherland Models

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    We extend the study on the algebraic structure of the su(n)su(n) color Calogero-Sutherland models to the case of gl(n∣m)gl(n|m) color CS model and show that the generators of the super-Yangian Y(gl(n∣m))Y(gl(n|m)) can be obtained from two gl(n∣m)gl(n|m) loop algebras. Also, a super W∞W_{\infty} algebra for the SUSY CS model is constructed.Comment: LaTeX, 13 page

    A precise determination of the top-quark pole mass

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    The Principle of Maximum Conformality (PMC) provides a systematic way to eliminate the renormalization scheme and renormalization scale uncertainties for high-energy processes. We have observed that by applying PMC scale-setting, one obtains comprehensive and self-consistent pQCD predictions for the top-quark pair total cross-section and the top-quark pair forward-backward asymmetry in agreement with the measurements at the Tevatron and LHC. As a step forward, in the present paper, we determine the top-quark pole mass via a detailed comparison of the top-quark pair cross-section with the measurements at the Tevatron and LHC. The results for the top-quark pole mass are mt=174.6−3.2+3.1m_t=174.6^{+3.1}_{-3.2} GeV for the Tevatron with S=1.96\sqrt{S}=1.96 TeV, mt=173.7±1.5m_t=173.7\pm1.5 GeV and 174.2±1.7174.2\pm1.7 GeV for the LHC with S=7\sqrt{S} = 7 TeV and 88 TeV, respectively. Those predictions agree with the average, 173.34±0.76173.34\pm0.76 GeV, obtained from various collaborations via direct measurements. The consistency of the pQCD predictions using the PMC with all of the collider measurements at different energies provides an important verification of QCD.Comment: 10 pages, 6 figures. Revised version to be published in Eur.Phys.J.

    A Novel Chaotic Particle Swarm Optimization Algorithm for Parking Space Guidance

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    An evolutionary approach of parking space guidance based upon a novel Chaotic Particle Swarm Optimization (CPSO) algorithm is proposed. In the newly proposed CPSO algorithm, the chaotic dynamics is combined into the position updating rules of Particle Swarm Optimization to improve the diversity of solutions and to avoid being trapped in the local optima. This novel approach, that combines the strengths of Particle Swarm Optimization and chaotic dynamics, is then applied into the route optimization (RO) problem of parking lots, which is an important issue in the management systems of large-scale parking lots. It is used to find out the optimized paths between any source and destination nodes in the route network. Route optimization problems based on real parking lots are introduced for analyzing and the effectiveness and practicability of this novel optimization algorithm for parking space guidance have been verified through the application results
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