Study of Light Scalar Meson Structure in D1D_1 decay

We study the quark structure of the sigma meson through the decay of $D_1(2430)$ meson by constructing an effective Lagrangian for charmed mesons interacting with light mesons based on the chiral symmetry and heavy quark symmetry. Within the linear realization of the chiral symmetry, we include the P-wave charmed mesons ($D_1(2430)$, $D_0(2400)$) as the chiral partners of ($D^\ast$, $D$), and the light scalar mesons as the chiral partner of the pseudoscalar mesons. In the light meson sector, both the $q\bar{q}$ and $qq\bar{q}\bar{q}$ states are incorporated respecting their different U(1)$_A$ transformation properties. We predict the $D_1 \to D\pi\pi$ decay width with two pions in the $I=0,\,l=0$ channel, which can be tested in the future experiment. We find that the width increases with the percentage of the $q\bar{q}$ content in the sigma meson.Comment: 5 pages, 2 figures, Contribution to KMI Inauguration Conference "Quest for the Origin of Particles and the Universe" (KMIIN), 24-26 Nov. 2011, KMI, Nagoya Universit

Precision era of the kinetic Sunyaev-Zeldovich effect: simulations, analytical models and observations and the power to constrain reionization

The kinetic SZ effect, which is the dominant CMB source at arc-minute scales and $\nu \sim 217$ Ghz, probes the ionized gas peculiar momentum up to the epoch of reionization and is a sensitive measure of the reionization history. We ran high resolution self-similar and $\Lambda$CDM hydro simulations and built an analytical model to study this effect. Our model reproduces the $\Lambda$CDM simulation results to several percent accuracy, passes various tests against self-similar simulations, and shows a wider range of applicability than previous analytical models. Our model in its continuous version is free of simulation limitations such as finite simulation box and finite resolution and allows an accurate prediction of the kinetic SZ power spectrum $C_l$. For the WMAP cosmology, we find $l^2C_l/(2\pi)\simeq 0.91 \times 10^{-12} [(1+z_{\rm reion})/10]^{0.34}(l/5000)^{0.23-0.015(z_{\rm reion}-9)}$ for the reionization redshift $6<z_{\rm reion}<20$ and $3000<l<9000$. The corresponding temperature fluctuation is several $\mu$K at these ranges. The dependence of $C_l$ on the reionization history allows an accurate measurement of the reionization epoch. For the Atacama cosmology telescope experiment, $C_l$ can be measured with $\sim 1$ accuracy. $C_l$ scales as $(\Omega_b h)^2 \sigma_8^{4\sim 6}$. Given cosmological parameters, ACT would be able to constrain $z_{\rm reion}$ with several percent accuracy. Some multi-reionization scenarios degenerate in the primary CMB temperature and TE measurement can be distinguished with $\sim 10 \sigma$ confidence.Comment: 14 pages, 7 figures. Accepted by MNRAS. We corrected the primary CMB power spectrum we used. We added discussions about the effects of lensing and relativistic SZ correctio. We withdraw a claim about the patchy reionizatio

The effect of asymmetry of the coil block on self-assembly in ABC coil-rod-coil triblock copolymers

Using the self-consistent field approach, the effect of asymmetry of the coil block on the microphase separation is focused in ABC coil-rod-coil triblock copolymers. For different fractions of the rod block $f_{\text B}$, some stable structures are observed, i.e., lamellae, cylinders, gyroid, and core-shell hexagonal lattice, and the phase diagrams are constructed. The calculated results show that the effect of the coil block fraction $f_{\text A}$ is dependent on $f_{\text B}$. When $f_{\text B}=0.2$, the effect of asymmetry of the coil block is similar to that of the ABC flexible triblock copolymers; When $f_{\text B}=0.4$, the self-assembly of ABC coil-rod-coil triblock copolymers behaves like rod-coil diblock copolymers under some condition. When $f_{\text B}$ continues to increase, the effect of asymmetry of the coil block reduces. For $f_{\text B}=0.4$, under the symmetrical and rather asymmetrical conditions, an increase in the interaction parameter between different components leads to different transitions between cylinders and lamellae. The results indicate some remarkable effect of the chain architecture on self-assembly, and can provide the guidance for the design and synthesis of copolymer materials.Comment: 9 pages, 3 figure

Variance-constrained multiobjective control and filtering for nonlinear stochastic systems: A survey

The multiobjective control and filtering problems for nonlinear stochastic systems with variance constraints are surveyed. First, the concepts of nonlinear stochastic systems are recalled along with the introduction of some recent advances. Then, the covariance control theory, which serves as a practical method for multi-objective control design as well as a foundation for linear system theory, is reviewed comprehensively. The multiple design requirements frequently applied in engineering practice for the use of evaluating system performances are introduced, including robustness, reliability, and dissipativity. Several design techniques suitable for the multi-objective variance-constrained control and filtering problems for nonlinear stochastic systems are discussed. In particular, as a special case for the multi-objective design problems, the mixed H 2 / H ∞ control and filtering problems are reviewed in great detail. Subsequently, some latest results on the variance-constrained multi-objective control and filtering problems for the nonlinear stochastic systems are summarized. Finally, conclusions are drawn, and several possible future research directions are pointed out

Effect of polymer concentration and length of hydrophobic end block on the unimer-micelle transition broadness in amphiphilic ABA symmetric triblock copolymer solutions

The effects of the length of each hydrophobic end block N_{st} and polymer concentration \bar{\phi}_{P} on the transition broadness in amphiphilic ABA symmetric triblock copolymer solutions are studied using the self-consistent field lattice model. When the system is cooled, micelles are observed, i.e.,the homogenous solution (unimer)-micelle transition occurs. When N_{st} is increased, at fixed \bar{\phi}_{P}, micelles occur at higher temperature, and the temperature-dependent range of micellar aggregation and half-width of specific heat peak for unimer-micelle transition increase monotonously. Compared with associative polymers, it is found that the magnitude of the transition broadness is determined by the ratio of hydrophobic to hydrophilic blocks, instead of chain length. When \bar{\phi}_{P} is decreased, given a large N_{st}, the temperature-dependent range of micellar aggregation and half-width of specific heat peak initially decease, and then remain nearly constant. It is shown that the transition broadness is concerned with the changes of the relative magnitudes of the eductions of nonstickers and solvents from micellar cores.Comment: 8 pages, 4 figure

Determination of f+K(0)f_+^K(0) and Extraction of ∣Vcs∣|V_{cs}| from Semileptonic DD Decays

By globally analyzing all existing measured branching fractions and partial rates in different four momentum transfer-squared $q^2$ bins of $D\to Ke^+\nu_e$ decays, we obtain the product of the form factor and magnitude of CKM matrix element $V_{cs}$ to be $f_+^K(0)|V_{cs}|=0.717\pm0.004$. With this product, we determine the $D\to K$ semileptonic form factor $f_+^K(0)=0.737\pm0.004\pm0.000$ in conjunction with the value of $|V_{cs}|$ determined from the SM global fit. Alternately, with the product together with the input of the form factor $f_+^K(0)$ calculated in lattice QCD recently, we extract $|V_{cs}|^{D\to Ke^+\nu_e}=0.962\pm0.005\pm0.014$, where the error is still dominated by the uncertainty of the form factor calculated in lattice QCD. Combining the $|V_{cs}|^{D_s^+\to\ell^+\nu_\ell}=1.012\pm0.015\pm0.009$ extracted from all existing measurements of $D^+_s\to\ell^+\nu_\ell$ decays and $|V_{cs}|^{D\to Ke^+\nu_e}=0.962\pm0.005\pm0.014$ together, we find the most precisely determined $|V_{cs}|$ to be $|V_{cs}|=0.983\pm0.011$, which improves the accuracy of the PDG'2014 value $|V_{cs}|^{\rm PDG'2014}=0.986\pm0.016$ by $45\%$