The Consistent Result of Cosmological Constant From Quantum Cosmology and Inflation with Born-Infeld Scalar Field

The Quantum cosmology with Born-Infeld(B-I) type scalar field is considered. In the extreme limits of small cosmological scale factor the wave function of the universe can also be obtained by applying the methods developed by Hartle-Hawking(H-H) and Vilenkin. H-H wave function predicts that most Probable cosmological constant $\Lambda$ equals to $\frac{1}{\eta}$($\frac{1}{2\eta}$ equals to the maximum of the kinetic energy of scalar field). It is different from the original results($\Lambda=0$) in cosmological constant obtained by Hartle-Hawking. The Vilenkin wave function predicts a nucleating unverse with largest possible cosmological constant and it is larger than $1/\eta$. The conclusions have been nicely to reconcile with cosmic inflation. We investigate the inflation model with B-I type scalar field, and find that $\eta$ depends on the amplitude of tensor perturbation $\delta_h$, with the form $\frac{1}{\eta}\simeq \frac{m^2}{12\pi[(\frac{9\delta_{\Phi}^2}{N \delta_h^2})^2-1]}.$ The vacuum energy in inflation epoch depends on the tensor-to-scalar ratio $\frac{\delta_h}{\delta_{\Phi}}$. The amplitude of the tensor perturbation ${\delta_{h}}$ can, in principle, be large enough to be discovered. However, it is only on the border of detectability in future experiments. If it has been observed in future, this is very interesting to determine the vacuum energy in inflation epoch.Comment: 12 pages, one figure, references added, accepted by European Physical Journal

Parametrization of Born-Infeld Type Phantom Dark Energy Model

Applying the parametrization of dark energy density, we can construct directly independent-model potentials. In Born-Infeld type phantom dark energy model, we consider four special parametrization equation of state parameter. The evolutive behavior of dark energy density with respect to red-shift $z$, potentials with respect to $\phi$ and $z$ are shown mathematically. Moreover, we investigate the effect of parameter $\eta$ upon the evolution of the constructed potential with respect to $z$. These results show that the evolutive behavior of constructed Born-Infeld type dark energy model is quite different from those of the other models.Comment: 5 pages, 4 figures, Accepted for publication in Astrophysics & Space Scienc

Born-Infeld Type Phantom Model in the ω−ω′\omega-\omega' Plane

In this paper, we investigate the dynamics of Born-Infeld(B-I) phantom model in the $\omega-\omega'$ plane, which is defined by the equation of state parameter for the dark energy and its derivative with respect to $N$(the logarithm of the scale factor $a$). We find the scalar field equation of motion in $\omega-\omega'$ plane, and show mathematically the property of attractor solutions which correspond to $\omega_\phi\sim-1$, $\Omega_\phi=1$, which avoid the "Big rip" problem and meets the current observations well.Comment: 6 pages, 3 figures, some references adde

Nonlinear hydro turbine model having a surge tank.

yesThis paper models a hydro turbine based on the dynamic description of the hydraulic system having a surge tank and elastic water hammer. The dynamic of the hydraulic system is transformed from transfer function form into the differential equation model in relative value. This model is then combined with the motion equation of the main servomotor to form the nonlinear model of the hydro turbine, in which the power of the hydro turbine is calculated using algebraic equation. A new control model is thus proposed in which the dynamic of the surge tank is taken as an additional input of control items. As such, the complex hydraulic system is decomposed into a classical one penstock and one machine model with an additional input control. Therefore, the order of the system is descended. As a result, the feasibility of the system is largely improved. The simulated results show that the additional input of the surge tank is effective and the proposed method is realizable.National Natural Science Foundation of China (50839003, 50949037, 51179079), Natural Science Foundation of Yunnan Province (No. 2008GA027

OmOm Diagnostic for Dilaton Dark Energy

$Om$ diagnostic can differentiate between different models of dark energy without the accurate current value of matter density. We apply this geometric diagnostic to dilaton dark energy(DDE) model and differentiate DDE model from LCDM. We also investigate the influence of coupled parameter $\alpha$ on the evolutive behavior of $Om$ with respect to redshift $z$. According to the numerical result of $Om$, we get the current value of equation of state $\omega_{\sigma0}$=-0.952 which fits the WMAP5+BAO+SN very well.Comment: 6 pages and 6 figures

Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-

We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi --> D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7 J/Psi events collected with the BESII detector at the BEPC. No excess of signal above background is observed, and 90% confidence level upper limits on the branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi --> D- e+ nu_e + c.c.) D0bar e+ e- + c.c.)<1.1*10^-5Comment: 10 pages, 4 figure

Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV

By analyzing the data sets of 17.3 pb$^{-1}$ taken at $\sqrt{s}=3.773$ GeV and 6.5 pb$^{-1}$ taken at $\sqrt{s}=3.650$ GeV with the BESII detector at the BEPC collider, we have measured the observed cross sections for 12 exclusive light hadron final states produced in $e^+e^-$ annihilation at the two energy points. We have also set the upper limits on the observed cross sections and the branching fractions for $\psi(3770)$ decay to these final states at 90% C.L.Comment: 8 pages, 5 figur

Measurements of psi(2S) decays to octet baryon-antibaryon pairs

With a sample of 14 million psi(2S) events collected by the BESII detector at the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their branching ratios are determined to be (3.36+-0.09+-0.24)*10E-4, (3.39+-0.20+-0.32)*10E-4, (2.35+-0.36+-0.32)*10E-4, (3.03+-0.40+-0.32)*10E-4, respectively. In the decay psi(2S)->p p-bar, the angular distribution parameter alpha is determined to be 0.82+-0.17+-0.04.Comment: 8 pages, 8 figure

Measurements of the observed cross sections for e+e−→e^+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

By analyzing the data sets of 17.3, 6.5 and 1.0 pb$^{-1}$ taken, respectively, at $\sqrt s= 3.773$, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for $e^+e^-\to \pi^+\pi^-\pi^0\pi^0$, $K^+K^-\pi^0\pi^0$, $2(\pi^+\pi^-\pi^0)$, $K^+K^-\pi^+\pi^-\pi^0\pi^0$ and $3(\pi^+\pi^-)\pi^0\pi^0$ 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 $\psi(3770)$ decay into these final states at 90% C.L..Comment: 7 pages, 2 figure

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

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