Estimating Form Factors of Bs→Ds(∗)B_s\rightarrow D_s^{(*)} and their Applications to Semi-leptonic and Non-leptonic Decays

$B_s^0\rightarrow D_s^{-}$ and $B_s^0\rightarrow D_s^{*-}$ weak transition form factors are estimated for the whole physical region with a method based on an instantaneous approximated Mandelstam formulation of transition matrix elements and the instantaneous Bethe-Salpeter equation. We apply the estimated form factors to branching ratios, CP asymmetries and polarization fractions of non-leptonic decays within the factorization approximation. And we study the non-factorizable effects and annihilation contributions with the perturbative QCD approach. The branching ratios of semi-leptonic $B_s^0\rightarrow D_s^{(*)-}l^+\nu_l$ decays are also evaluated. We show that the calculated decay rates agree well with the available experimental data. The longitudinal polarization fraction of $B_s\rightarrow D_s^*V(A)$ decays are $\sim0.8$ when $V(A)$ denotes a light meson, and are $\sim0.5$ when $V(A)$ denotes a $D_q$ ($q=d,s$) meson.Comment: Final version published in J Phys. G 39 (2012) 045002 (Title also changed

Supervisory evolutionary optimization strategy for adaptive maintenance schedules

10.1109/ISIE.2011.5984204Proceedings - ISIE 2011: 2011 IEEE International Symposium on Industrial Electronics1137-114

Grazing activity increases decomposition of yak dung and litter in an alpine meadow on the Qinghai-Tibet plateau

Publishe

The BcB_c Decays to PP-wave Charmonium by Improved Bethe-Salpeter Approach

We re-calculate the exclusive semileptonic and nonleptonic decays of $B_c$ meson to a $P$-wave charmonium in terms of the improved Bethe-Salpeter (B-S) approach, which is developed recently. Here the widths for the exclusive semileptonic and nonleptonic decays, the form factors, and the charged lepton spectrums for the semileptonic decays are precisely calculated. To test the concerned approach by comparing with experimental measurements when the experimental data are available, and to have comparisons with the other approaches the results obtained by the approach and those by some approaches else as well as the original B-S approach, which appeared in literature, are comparatively presented and discussed.Comment: 33 pages, 5 figures, 3 table

A systematic study of Rayleigh-Brillouin scattering in air, N2 and O2 gases

Spontaneous Rayleigh-Brillouin scattering experiments in air, N2 and O2 have been performed for a wide range of temperatures and pressures at a wavelength of 403 nm and at a 90 degrees scattering angle. Measurements of the Rayleigh-Brillouin spectral scattering profile were conducted at high signal-to-noise ratio for all three species, yielding high-quality spectra unambiguously showing the small differences between scattering in air, and its constituents N2 and O2. Comparison of the experimental spectra with calculations using the Tenti S6 model, developed in 1970s based on linearized kinetic equations for molecular gases, demonstrates that this model is valid to high accuracy. After previous measurements performed at 366 nm, the Tenti S6 model is here verified for a second wavelength of 403 nm. Values for the bulk viscosity for the gases are derived by optimizing the model to the measurements. It is verified that the bulk viscosity parameters obtained from previous experiments at 366 nm, are valid for wavelengths of 403 nm. Also for air, which is treated as a single-component gas with effective gas transport coefficients, the Tenti S6 treatment is validated for 403 nm as for the previously used wavelength of 366 nm, yielding an accurate model description of the scattering profiles for a range of temperatures and pressures, including those of relevance for atmospheric studies. It is concluded that the Tenti S6 model, further verified in the present study, is applicable to LIDAR applications for exploring the wind velocity and the temperature profile distributions of the Earth's atmosphere. Based on the present findings, predictions can be made on the spectral profiles for a typical LIDAR backscatter geometry, which deviate by some 7 percent from purely Gaussian profiles at realistic sub-atmospheric pressures occurring at 3-5 km altitude in the Earth's atmosphere

Lagrangian Approach for Simulating Supercooled Large Droplets’ Impingement Effect

This document is the Accepted Manuscript version of the following article: C. Wang, S. Chang, and H. Wu, "Lagrangian Approach for Simulating Supercooled Large Droplets’ Impingement Effect", Journal of Aircraft, Vol. 52, No. 2 (2015), pp. 524-537. The Version of Record is available online at doi: https://doi.org/10.2514/1.C032765.In this paper, a droplet tracking method and a splashing model have been developed to calculate the droplet collection efficiency in a supercooled-large-droplets regime using the Lagrangian computational method. In the droplet tracking method, the droplet deformation and the droplet-wall effects (for example, splashing, bouncing, and reimpingement), which are the typical cases in a supercooled-large-droplets regime, are incorporated by introducing the mass residual ratio. The effects of the transition from the conventional-small-droplets impingement to a supercooled-large-droplets impingement, as well as the splashed secondary droplets, on the droplet collection are considered in the current splashing model. The performance and capacities of the droplet tracking method and the supercooled-large-droplets splashing model are validated against the alternative experimental reference data. The mass loss ratio and the mass back ratio are introduced in order to explore the distribution and the quantity of the mass loss and mass back caused by droplet splashing and reimpingement. The predicted results show that the quantity and the distribution range of the mass back ratio on airfoil surfaces are relatively lower than those of the mass loss ratio. A significant mass back is observed when the airfoil is contaminated with ice. No mass loss or mass back is observed beyond the impinging region for the given conditions.Peer reviewe

Spectrum for Heavy Quankonia and Mixture of the Relevant Wave Functions within the Framework of Bethe-Salpeter Equation

Considering the fact that some excited states of the heavy quarkonia (charmonium and bottomonium) still missing in experimental observations and potential applications of the relevant wave functions of the bound states, we re-analyze the spectrum and the relevant wave functions of the heavy quarkonia within the framework of Bethe-Salpeter (B.S.) equation with a proper QCD-inspired kernel. Such a kernel for the heavy quarkonia, relating to potential of non-relativistic quark model, is instantaneous, so we call the corresponding B.S. equation as BS-In equation throughout the paper. Particularly, a new way to solve the B.S. equation, which is different from the traditional ones, is proposed here, and with it not only the known spectrum for the heavy quarkonia is re-generated, but also an important issue is brought in, i.e., the obtained solutions of the equation `automatically' include the 'fine', 'hyperfine' splittings and the wave function mixture, such as $S-D$ wave mixing in $J^{PC}=1^{--}$ states, $P-F$ wave mixing in $J^{PC}=2^{++}$ states for charmonium and bottomonium etc. It is pointed out that the best place to test the wave mixture probably is at $Z$-factory ($e^+e^-$ collider running at $Z$-boson pole with extremely high luminosity).Comment: 26 pages, 8 figure

A feature based frequency domain analysis algorithm for fault detection of induction motors

10.1109/ICIEA.2011.5975545Proceedings of the 2011 6th IEEE Conference on Industrial Electronics and Applications, ICIEA 201127-3

The magnetic dipole transitions in the (cbˉ)(c\bar{b}) binding system

The magnetic dipole transitions between the vector mesons $B_c^*$ and their relevant pseudoscalar mesons $B_c$ ($B_c$, $B_c^*$, $B_c(2S)$, $B_c^*(2S)$, $B_c(3S)$ and $B_c^*(3S)$ etc, the binding states of $(c\bar{b})$ system) of the $B_c$ family are interesting. To see the `hyperfine' splitting due to spin-spin interaction is an important topic for understanding the spin-spin interaction and the spectrum of the the $(c\bar{b})$ binding system. The knowledge about the magnetic dipole transitions is also very useful for identifying the vector boson $B_c^*$ mesons experimentally, whose masses are just slightly above the masses of their relevant pseudoscalar mesons $B_c$ accordingly. Considering the possibility to observe the vector mesons via the transitions at $Z^0$ factory and the potentially usages of the theoretical estimate on the transitions, we fucus our efforts on calculating the magnetic dipole transitions, i.e. precisely to calculate the rates for the transitions such as decays $B_c^*\to B_c\gamma$ and $B_c^*\to B_c e^+e^-$, and particularly work in the Behte-Salpeter framework. In the estimate, as a typical example, we carefully investigate the dependance of the rate $\Gamma(B_c^*\to B_c\gamma)$ on the mass difference $\Delta M=M_{B_c^*}-M_{B_c}$ as well.Comment: 10 pages, 2 figures, 1 tabl