63 research outputs found

    Detrended fluctuation analysis on the correlations of complex networks under attack and repair strategy

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    We analyze the correlation properties of the Erdos-Renyi random graph (RG) and the Barabasi-Albert scale-free network (SF) under the attack and repair strategy with detrended fluctuation analysis (DFA). The maximum degree k_max, representing the local property of the system, shows similar scaling behaviors for random graphs and scale-free networks. The fluctuations are quite random at short time scales but display strong anticorrelation at longer time scales under the same system size N and different repair probability p_re. The average degree , revealing the statistical property of the system, exhibits completely different scaling behaviors for random graphs and scale-free networks. Random graphs display long-range power-law correlations. Scale-free networks are uncorrelated at short time scales; while anticorrelated at longer time scales and the anticorrelation becoming stronger with the increase of p_re.Comment: 5 pages, 4 figure

    Au+Au Reactions at the AGS: Experiments E866 and E917

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    Particle production and correlation functions from Au+Au reactions have been measured as a function of both beam energy (2-10.7AGeV) and impact parameter. These results are used to probe the dynamics of heavy-ion reactions, confront hadronic models over a wide range of conditions and to search for the onset of new phenomena.Comment: 12 pages, 14 figures, Talk presented at Quark Matter '9

    Measurements of the Mass and Full-Width of the ηc\eta_c Meson

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    In a sample of 58 million J/ψJ/\psi events collected with the BES II detector, the process J/ψγηc\psi\to\gamma\eta_c is observed in five different decay channels: γK+Kπ+π\gamma K^+K^-\pi^+\pi^-, γπ+ππ+π\gamma\pi^+\pi^-\pi^+\pi^-, γK±KS0π\gamma K^\pm K^0_S \pi^\mp (with KS0π+πK^0_S\to\pi^+\pi^-), γϕϕ\gamma \phi\phi (with ϕK+K\phi\to K^+K^-) and γppˉ\gamma p\bar{p}. From a combined fit of all five channels, we determine the mass and full-width of ηc\eta_c to be mηc=2977.5±1.0(stat.)±1.2(syst.)m_{\eta_c}=2977.5\pm1.0 ({stat.})\pm1.2 ({syst.}) MeV/c2c^2 and Γηc=17.0±3.7(stat.)±7.4(syst.)\Gamma_{\eta_c} = 17.0\pm3.7 ({stat.})\pm7.4 ({syst.}) MeV/c2c^2.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.

    A Measurement of Psi(2S) Resonance Parameters

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    Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) total width; partial widths to hadrons, pi+pi- J/Psi, muons; and corresponding branching fractions have been determined to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)= (2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)= (97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%, respectively.Comment: 8 pages, 6 figure

    Epidemiology of facial fractures: Incidence, prevalence and years lived with disability estimates from the Global Burden of Disease 2017 study

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    Background: The Global Burden of Disease Study (GBD) has historically produced estimates of causes of injury such as falls but not the resulting types of injuries that occur. The objective of this study was to estimate the global incidence, prevalence and years lived with disability (YLDs) due to facial fractures and to estimate the leading injurious causes of facial fracture. Methods: We obtained results from GBD 2017. First, the study estimated the incidence from each injury cause (eg, falls), and then the proportion of each cause that would result in facial fracture being the most disabling injury. Incidence, prevalence and YLDs of facial fractures are then calculated across causes. Results: Globally, in 2017, there were 7 538 663 (95% uncertainty interval 6 116 489 to 9 4

    Measurement of Branching Ratios for ηc\eta_c Hadronic Decays

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    In a sample of 58 million J/ψJ/\psi events collected with the BES II detector, the process J/ψγηc\psi\to\gamma\eta_c is observed in five decay channels: ηcK+Kπ+π\eta_c \to K^+K^-\pi^+\pi^-, π+ππ+π\pi^+\pi^-\pi^+\pi^-, K±KS0πK^\pm K^0_S \pi^\mp (with KS0π+πK^0_S\to\pi^+\pi^-), ϕϕ\phi\phi (with ϕK+K\phi\to K^+K^-) and ppˉp\bar{p}. From these signals, we determine Br(J/ψγηc)×Br(ηcK+Kπ+π)Br(J/\psi\to\gamma\eta_c)\times Br(\eta_c\to K^+K^-\pi^+\pi^-) =(1.5±0.2±0.2)×104=(1.5\pm0.2\pm0.2)\times10^{-4}, Br(J/ψγηc)×Br(ηcπ+ππ+π)Br(J/\psi\to\gamma\eta_c)\times Br(\eta_c\to \pi^+\pi^-\pi^+\pi^-) =(1.3±0.2±0.4)×104=(1.3\pm0.2\pm0.4)\times10^{-4}, Br(J/ψγηc)×Br(ηcK±KS0π)Br(J/\psi\to\gamma\eta_c)\times Br(\eta_c\to K^\pm K_{S}^{0}\pi^\mp) =(2.2±0.3±0.5)×104=(2.2\pm0.3\pm0.5)\times10^{-4}, Br(J/ψγηc)×Br(ηcϕϕ)Br(J/\psi\to\gamma\eta_c)\times Br(\eta_c\to \phi\phi) =(3.3±0.6±0.6)×105=(3.3\pm0.6\pm0.6)\times10^{-5} and Br(J/ψγηc)×Br(ηcppˉ)Br(J/\psi\to\gamma\eta_c)\times Br(\eta_c\to p\bar{p}) =(1.9±0.3±0.3)×105=(1.9\pm0.3\pm0.3)\times10^{-5}.Comment: 8 pages, 1 figures and 4 table. Submitted to Phys. Lett.

    Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-

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    Evidence of ψ(3770)\psi(3770) decays to a non-DDˉ{D \bar D} final state is observed. A total of 11.8±4.8±1.311.8 \pm 4.8 \pm 1.3 \psi(3770) \to \PPJP events are obtained from a data sample of 27.7 pb1\rm {pb^{-1}} taken at center-of-mass energies around 3.773 GeV using the BES-II detector at the BEPC. The branching fraction is determined to be BF(\psi(3770) \to \PPJP)=(0.34\pm 0.14 \pm 0.09)%, corresponding to the partial width of \Gamma(\psi(3770) \to \PPJP) = (80 \pm 33 \pm 23) keV.Comment: 8 pages, 7 figures, Submitted to Physics Letters

    Measurements of J/psi --> p \bar{p}

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    The process J/\psi --> p \bar{p} is studied using 57.7 X 10^6 J/\psi events collected with the BESII detector at the Beijing Electron Positron Collider. The branching ratio is determined to be Br(J/\psi --> p \bar{p})=(2.26 +- 0.01 +- 0.14) X 10^{-3}, and the angular distribution is well described by \frac{dN}{d cos\theta_p}=1+\alpha\cos^2\theta_p with \alpha = 0.676 +- 0.036 +- 0.042, where \theta_p is the angle between the proton and beam directions. The value of \alpha obtained is in good agreement with the predictions of first-order QCD.Comment: 6 pages, 2 figures, RevTex4, Submitted to Phys.Lett.

    Search for K_S K_S in J/psi and psi(2S) decays

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    The CP violating processes J/psi-->K_S K_S and psi(2S)-->K_S K_S are searched for using samples of 58 million J/psi and 14 million psi(2S) events collected with the Beijing Spectrometer at the Beijing Electron Positron Collider. No signal is observed, and upper limits on the decay branching ratios are determined to be BR(J/psi-->K_S K_S) K_S K_S) < 4.6x10^{-6} at the 95% confidence level.Comment: 6 pages, 4 figures, submitted to Phys. Lett.

    A Study of J/psi-->gamma gamma V(rho,phi) Decays with the BESII Detector

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    Using a sample of 58×10658\times 10^6 J/ψJ/\psi events collected with the BESII detector, radiative decays J/ψγγVJ/\psi\to\gamma\gamma V, where V=ρV=\rho or ϕ\phi, are studied. A resonance around 1420 MeV/c2^2 (X(1424)) is observed in the γρ\gamma\rho mass spectrum. Its mass and width are measured to be 1424±10(stat)±11(sys)1424\pm 10(stat)\pm 11(sys) MeV/c2^2 and 101.0±8.8±8.8 101.0\pm 8.8 \pm 8.8 MeV/c2^2, respectively, and its branching ratio B(J/ψγX(1424)γγρ)B(J/\psi\to \gamma X(1424)\to \gamma \gamma \rho) is determined to be (1.07±0.17±0.11)×104(1.07\pm0.17 \pm 0.11)\times 10^{-4}. A search for X(1424)γϕX(1424)\to \gamma\phi yields a 95% C.L. upper limit B(J/ψγX(1424)γγϕ)<0.82×104B(J/\psi\to \gamma X(1424)\to \gamma\gamma \phi) < 0.82 \times 10^{-4}.Comment: 10 pages, 5 figures, submitted to PL
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