40 research outputs found

    A Survey of Finite Algebraic Geometrical Structures Underlying Mutually Unbiased Quantum Measurements

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    The basic methods of constructing the sets of mutually unbiased bases in the Hilbert space of an arbitrary finite dimension are discussed and an emerging link between them is outlined. It is shown that these methods employ a wide range of important mathematical concepts like, e.g., Fourier transforms, Galois fields and rings, finite and related projective geometries, and entanglement, to mention a few. Some applications of the theory to quantum information tasks are also mentioned.Comment: 20 pages, 1 figure to appear in Foundations of Physics, Nov. 2006 two more references adde

    Measurements of the observed cross sections for e+ee^+e^-\to exclusive light hadrons containing π0π0\pi^0\pi^0 at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV

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    By analyzing the data sets of 17.3, 6.5 and 1.0 pb1^{-1} taken, respectively, at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for e+eπ+ππ0π0e^+e^-\to \pi^+\pi^-\pi^0\pi^0, K+Kπ0π0K^+K^-\pi^0\pi^0, 2(π+ππ0)2(\pi^+\pi^-\pi^0), K+Kπ+ππ0π0K^+K^-\pi^+\pi^-\pi^0\pi^0 and 3(π+π)π0π03(\pi^+\pi^-)\pi^0\pi^0 at the three energy points. Based on these cross sections we set the upper limits on the observed cross sections and the branching fractions for ψ(3770)\psi(3770) decay into these final states at 90% C.L..Comment: 7 pages, 2 figure

    Partial wave analysis of J/\psi \to \gamma \phi \phi

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    Using 5.8×107J/ψ5.8 \times 10^7 J/\psi events collected in the BESII detector, the radiative decay J/ψγϕϕγK+KKS0KL0J/\psi \to \gamma \phi \phi \to \gamma K^+ K^- K^0_S K^0_L is studied. The ϕϕ\phi\phi invariant mass distribution exhibits a near-threshold enhancement that peaks around 2.24 GeV/c2c^{2}. A partial wave analysis shows that the structure is dominated by a 0+0^{-+} state (η(2225)\eta(2225)) with a mass of 2.240.02+0.030.02+0.032.24^{+0.03}_{-0.02}{}^{+0.03}_{-0.02} GeV/c2c^{2} and a width of 0.19±0.030.04+0.060.19 \pm 0.03^{+0.06}_{-0.04} GeV/c2c^{2}. The product branching fraction is: Br(J/ψγη(2225))Br(η(2225)ϕϕ)=(4.4±0.4±0.8)×104Br(J/\psi \to \gamma \eta(2225))\cdot Br(\eta(2225)\to \phi\phi) = (4.4 \pm 0.4 \pm 0.8)\times 10^{-4}.Comment: 11 pages, 4 figures. corrected proof for journa

    Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays

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    By analyzing about 33 pb1\rm pb^{-1} data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the neutral and charged DD inclusive semimuonic decays to be BF(D0μ+X)=(6.8±1.5±0.7)BF(D^0 \to \mu^+ X) =(6.8\pm 1.5\pm 0.7)% and BF(D+μ+X)=(17.6±2.7±1.8)BF(D^+ \to \mu^+ X) =(17.6 \pm 2.7 \pm 1.8)%, and determine the ratio of the two branching fractions to be BF(D+μ+X)BF(D0μ+X)=2.59±0.70±0.25\frac{BF(D^+ \to \mu^+ X)}{BF(D^0 \to \mu^+ X)}=2.59\pm 0.70 \pm 0.25

    A study of charged kappa in J/ψK±Ksππ0J/\psi \to K^{\pm} K_s \pi^{\mp} \pi^0

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    Based on 58×10658 \times 10^6 J/ψJ/\psi events collected by BESII, the decay J/ψK±Ksππ0J/\psi \to K^{\pm} K_s \pi^{\mp} \pi^0 is studied. In the invariant mass spectrum recoiling against the charged K(892)±K^*(892)^{\pm}, the charged κ\kappa particle is found as a low mass enhancement. If a Breit-Wigner function of constant width is used to parameterize the kappa, its pole locates at (849±7714+18)i(256±4022+46)(849 \pm 77 ^{+18}_{-14}) -i (256 \pm 40 ^{+46}_{-22}) MeV/c2c^2. Also in this channel, the decay J/ψK(892)+K(892)J/\psi \to K^*(892)^+ K^*(892)^- is observed for the first time. Its branching ratio is (1.00±0.190.32+0.11)×103(1.00 \pm 0.19 ^{+0.11}_{-0.32}) \times 10^{-3}.Comment: 14 pages, 4 figure

    Measurements of the observed cross sections for e+e -> exclusive light hadrons containing K^S_0 meson at \sqrt{s} = 3.773 and 3.650 GeV

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    By analyzing the data sets of 17.3 pb1^{-1} taken at s=3.773\sqrt s= 3.773 GeV and of 6.5 pb1^{-1} taken at s=3.650\sqrt s= 3.650 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for the exclusive light hadron final states of KS0Kπ+K_S^0K^-\pi^+, KS0Kπ+π0K_S^0K^-\pi^+\pi^0, KS0Kπ+π+πK_S^0K^-\pi^+\pi^+\pi^-, KS0Kπ+π+ππ0K_S^0K^-\pi^+\pi^+\pi^-\pi^0, KS0Kπ+π+π+ππK_S^0K^-\pi^+\pi^+\pi^+\pi^-\pi^- and KS0Kπ+π0π0K_S^0K^-\pi^+\pi^0\pi^0 produced in e+ee^+ e^- annihilation at the two energy points. We set the upper limits on the observed cross sections and the branching fractions for ψ(3770)\psi(3770) decay to these final states at 90% C.L..Comment: 6 pages, 1 figur

    Study of J/Psi decays into eta Kstar Kstar-bar

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    We report the first observation of \mPJpsi \to \mPeta\mPKst\mAPKst decay in a \mPJpsi sample of 58 million events collected with the BESII detector. The branching fraction is determined to be (1.15±0.13±0.22)×103(1.15 \pm 0.13 \pm 0.22)\times 10^{-3}. The selected signal event sample is further used to search for the \mPY resonance through \mPJpsi \to \mPeta \mPY, \mPY\to\mPKst\mAPKst. No evidence of a signal is seen. An upper limit of \mathrm{Br}(\mPJpsi \to \mPeta \mPY)\cdot\mathrm{Br}(\mPY\to\mPKst\mAPKst) < 2.52\times 10^{-4} is set at the 90% confidence level.Comment: 11 pages, 4 figure

    Meta-analysis of association between ALDH2 rs671 polymorphism and essential hypertension in Asian populations

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    Background: Mitochondrial aldehyde dehydrogenase-2 (ALDH2) is an enzyme that oxidizes acetaldehyde into acetic acid during alcohol metabolism. Many studies indicate that the rs671 GG genotype in the ALDH2 gene may play a critical role in increasing the risk of essential hypertension (EH) associated with alcohol consumption, which predominantly occurs in men. However, the literature is inconclusive in this regard. This meta-analysis aims to derive a more precise estimation of the relationship between the rs671 polymorphism and EH for both male and female drinkers and nondrinkers. Methods: Ten cohort and case-control studies were included in the analysis with a total of 12,161 subjects; 7,062 patients and 5,099 healthy controls. Results: Our results show that the rs671 GG genotype was associated with an increased risk of EH compared with the AG+AA genotype (OR = 1.27, 95 % CI = 1.17–1.37, p \u3c 0.00001). When comparing male and female subjects, only among male individuals was a higher risk of EH found in the GG genotype compared with the AG+ AA genotype (OR = 1.59, 95 % CI = 1.40–1.80, p \u3c 0.00001). By contrast, among female subjects, the risk of EH in the rs671 GG genotype did not differ from that detected in the AA + GG genotype. The proportion of patients with EH was significantly higher for the GG genotype carriers than for the AG+AA genotype carriers, both in the subset of drinkers (OR = 1.51, 95 % CI = 1.23–1.86, p \u3c 0.0001) and in that of nondrinkers (OR = 1.22, 95 % CI = 1.01–1.47, p = 0.03). In addition, among carriers of the GG genotype, the risk of EH among the drinkers was similar to that found in the nondrinkers’ subset (OR = 1.12, 95 %CI = 0.89–1.41, p = 0.34). Conclusions: Our meta-analysis demonstrates that the rs671 GG genotype increases the risks of EH, especially in men, and is independent of alcohol consumption

    Incorporating hydration force determined by boundary element method into stochastic dynamics

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    Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
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