2,165 research outputs found

    Stationary entanglement in N-atom subradiant degenerate cascade systems

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    We address ultracold NN-atom degenerate cascade systems and show that stationary subradiant states, already observed in the semiclassical regime, also exist in a fully quantum regime and for a small number of atoms. We explicitly evaluate the amount of stationary entanglement for the two-atom configuration and show full inseparability for the three-atom case. We also show that a continuous variable description of the systems is not suitable to detect entanglement due to the nonGaussianity of subradiant states.Comment: 4 figure

    Beautiful Baryons from Lattice QCD

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    We perform a lattice study of heavy baryons, containing one (Λb\Lambda_b) or two bb-quarks (Ξb\Xi_b). Using the quenched approximation we obtain for the mass of Λb\Lambda_b MΛb=5.728±0.144±0.018GeV. M_{\Lambda_b}= 5.728 \pm 0.144 \pm 0.018 {\rm GeV}. The mass splitting between the Λb\Lambda_b and the B-meson is found to increase by about 20\% if the light quark mass is varied from the chiral limit to the strange quark mass.Comment: 11 pages, Figures obtained upon request from [email protected]

    Witnessing entanglement in hybrid systems

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    We extend the definition of entanglement witnesses based on structure factors to the case in which the position of the scatterers is quantized. This allows us to study entanglement detection in hybrid systems. We provide several examples that show how these extra degrees of freedom affect the detection of entanglement by directly contributing to the measurement statistics. We specialize the proposed witness operators for a chain of trapped ions. Within this framework, we show how the collective vibronic state of the chain can act as an undesired quantum environment and how ions quantum motion can affect the entanglement detection. Finally, we investigate some specific cases where the method proposed leads to detection of hybrid entanglement.Comment: 6 pages, 4 figure

    Heavy-light baryonic mass splittings from the lattice

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    We present lattice estimates of the mass of the heavy-light baryons Λb\Lambda_b and Ξb\Xi_b obtained using propagating heavy quarks. For Λb\Lambda_b our result is MΛb=5.728±0.144±0.018M_{\Lambda_b}=5.728 \pm 0.144 \pm 0.018 GeV, after extrapolation to the continuum limit and in the quenched approximation.Comment: 3 pages postscript, Contribution to Lattice'9

    Axial anomalies in gauge theory by exact renormalization group method

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    The global chiral symmetry of a SU(2)SU(2) gauge theory is studied in the framework of renormalization group (RG). The theory is defined by the RG flow equations in the infrared cutoff \L and the boundary conditions for the relevant couplings. The physical theory is obtained at \L=0. In our approach the symmetry is implemented by choosing the boundary conditions for the relevant couplings not at the ultraviolet point \L=\L_0\to\infty but at the physical value \L=0. As an illustration, we compute the triangle axial anomalies.Comment: 11 pages + 1 appended EPS figure, LaTeX, UPRF 94-39

    First results with non-perturbative fermion improvement

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    We present initial results for light hadron masses and nucleon structure functions using a recent proposal for eliminating all O(a)O(a) effects from Wilson fermion simulations in the quenched approximation. With initially limited statistics, we find a much more linear APE plot and a value of the axial coupling gAg_A nearer to the experimental point than with comparable runs using unimproved Wilson fermions.Comment: 3 pages, 2 PostScript figures, LaTeX 2.09 with espcrc2.sty v2.6, amstex and epsf, talk presented at LATTICE96(phenomenology) by P. Stephenso

    Report on advances for pediatricians in 2018: allergy, cardiology, critical care, endocrinology, hereditary metabolic diseases, gastroenterology, infectious diseases, neonatology, nutrition, respiratory tract disorders and surgery.

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    This review reported notable advances in pediatrics that have been published in 2018. We have highlighted progresses in allergy, cardiology, critical care, endocrinology, hereditary metabolic diseases, gastroenterology, infectious diseases, neonatology, nutrition, respiratory tract disorders and surgery. Many studies have informed on epidemiologic observations. Promising outcomes in prevention, diagnosis and treatment have been reported. We think that advances realized in 2018 can now be utilized to ameliorate patient car

    Monte Carlo simulations and field transformation: the scalar case

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    We describe a new method in lattice field theory to compute observables at various values of the parameters lambda_i in the action S[phi,lambda_i]. Firstly one performs a single simulation of a ``reference action'' S[phi^r, lambda_i^r] with fixed lambda_i^r. Then the phi^r-configurations are transformed into those of a field phi distributed according to S[phi,lambda_i], apart from a ``remainder action'' which enters as a \break weight. In this way we measure the observables at values of lambda_i different from lambda_i^r. We study the performance of the algorithm in the case of the simplest renormalizable model, namely the phi^4 scalar theory on a four dimensional lattice and compare the method with the ``histogram'' technique of which it is a generalization.Comment: Latex, 23 pgs, 8 eps-figures include
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