ρ−ω\rho - \omega Mixing in J/ψ→VPJ/\psi\to VP Decays

The study on $\rho-\omega$ mixing is mainly focused on vector mesons decay with isospin I=1, namely $\rho(\omega)\to\pi^+\pi^-$ process. In this paper, we present the study of $\rho-\omega$ mixing in $\rho(\omega)\to\pi^+\pi^-\pi^0$ (I=0) using a flavor parameterization model for $J/\psi\to VP$ process. By fitting theoretical frame to PDG data, we obtain the SU(3)-breaking effect parameters $s_V=0.03\pm 0.12,\ s_P=0.17\pm 0.17$ and the $\rho-\omega$ mixing polarization operator $\Pi_{\rho \omega}=0.006\pm 0.011\text{\text{GeV}}^2$. The branching ratios are also renewed when mixing effect is incorporated: $Br(J/\psi\to \omega\pi^0) = (3.64 \pm 0.37)\times 10^{-4}$, $Br(J/\psi\to \omega\eta) = (1.48 \pm 0.17)\times 10^{-3}$, $Br(J/\psi\to \omega\eta^{\prime}) = (1.55\pm 0.56)\times 10^{-4}$; they are different from the corresponding PDG2012 values by 19%, 15% and 15%, respectively.Comment: Submitted to Chinese Physics C (CPC). 8 pages, 3 figures (one of them with 5 subfigures), 3 table

Description of dynamics of stock prices by a Langevin approach

We present a time-dependent Langevin description of dynamics of stock prices. Based on a simple sliding-window algorithm, the fluctuation of stock prices is discussed in the view of a time-dependent linear restoring force which is the linear approximation of the drift parameter in Langevin equation estimated from the financial time series. By choosing suitable weighted factor for the linear approximation, the relation between the dynamical effect of restoring force and the autocorrelation of the financial time series is deduced. We especially analyze the daily log-returns of S&P 500 index from 1950 to 1999. The significance of the restoring force towards the prices evolution are investigated from its two coefficients, slope coefficient and equilibrium position. The new simple form of the restoring force obtained both from statistical and theoretical analyses suggests that the Langevin approach can effectively present the macroscopical and the detail properties of the price evolution.Comment: 7 pages, 7 figures. Comments and suggestions are favore

On third Hankel determinants for subclasses of analytic functions and close-to-convex harmonic mappings

In this paper, we obtain the upper bounds to the third Hankel determinants for starlike functions of order $\alpha$, convex functions of order $\alpha$ and bounded turning functions of order $\alpha$. Furthermore, several relevant results on a new subclass of close-to-convex harmonic mappings are obtained. Connections of the results presented here to those that can be found in the literature are also discussed.Comment: 13 page

Topological antiferromagnetic spin-density-wave phase in an extended Kondo lattice model

By using an extended mean-field theory, we study the phase diagram of the topological Kondo lattice model on the honeycomb lattice at half-filling in which the conduction electrons are described by the Haldane model. Besides the well-defined Kondo insulator and normal antiferromagnetic spin-density-wave (N-SDW) state, it is found that a nontrivial topological antiferromagnetic SDW state (T-SDW) with a quantized Hall conductance is possible if the quasiparticle gap is dominated by the next-nearest-neighbor hopping rather than the antiferromagnetic order. By analyzing the low-energy effective Chern-Simon action and the corresponding chiral edge state, the T-SDW could be considered as a quantum anomalous Hall insulator with antiferromagnetic long-range order. This state is apparently beyond Landau-Ginzburg paradigm, which can be attributed to the interplay of quantum anomalous Hall effect and the subtle antiferromagnetic order in the Kondo-lattice-like model. While the transition between the SDW states and the Kondo insulator is found to be conventional (a first order transition), the transition between the N- and T-SDWs is, however, a topological quantum phase transition. Interestingly, such topological quantum phase transition can be described by Dirac fermions coupled to a U (1)Chern-Simon gauge field, which resembles the critical theory between bosonic integer quantum Hall phases and superfluid phase and also indicates that such a topological quantum phase transition may fall into the 3D-XY universal class. It is expected that the present work may shed light on the interplay between conduction electrons and the densely localized spins on the honeycomb lattice.Comment: 11pages,3figures. Fluctuation effect is included and critical theory for the topological quantum phase transition is also derive

Improved Algorithm for Reconstructing Singular Connection in Multi-Block CFD Applications

An improved algorithm is proposed for the reconstruction of singular connectivity from the available pairwise connections during preprocessing phase. To evaluate the performance of the algorithm, an in-house computational fluid dynamics (CFD) code is used in which high-order finite-difference method for spatial discretization running on the Tianhe-1A supercomputer is employed. Test cases with a varied amount of mesh points are chosen, and the test results indicate that the improved singular connection reconstruction algorithm can achieve a speedup factor of 1000X or more when compared with the naive search method adopted in the former version of our code. Moreover, the parallel efficiency can benefit from the strategy of local communication based on the algorithm.Comment: 10 pages, 3 figures, 2 tables. Pre-print versio

Low-energy effective theory and two distinct critical phases in a spin-1/2 frustrated three-leg spin tube

Motivated by the crystal structures of [(CuCl2tachH)3Cl]Cl2 and Ca3Co2O6, we develop a low-energy effective theory using the bosonization technique for a spin-1/2 frustrated three-leg spin tube with trigonal prism units in two limit cases. The features obtained with the effective theory are numerically elucidated by the density matrix renormalization group method. Three different quantum phases in the ground state of the system, say, one gapped dimerized phase and two distinct gapless phases, are identified, where the two gapless phases are found to have the conformal central charge c=1 and 3/2, respectively. Spin gaps, spin and dimer correlation functions, and the entanglement entropy are obtained. In particular, it is disclosed that the critical phase with c=3/2 is the consequence of spin frustrations, which might belong to the SU(2)k=2 Wess-Zumino-Witten-Novikov universality class, and is induced by the twist term in the bosonized Hamiltonian density.Comment: 5 pages, 6 figure

On a problem of Bharanedhar and Ponnusamy involving planar harmonic mappings

In this paper, we give a negative answer to a problem presented by Bharanedhar and Ponnusamy (Rocky Mountain J. Math. 44: 753--777, 2014) concerning univalency of a class of harmonic mappings. More precisely, we show that for all values of the involved parameter, this class contains a non-univalent function. Moreover, several results on a new subclass of close-to-convex harmonic mappings, which is motivated by work of Ponnusamy and Sairam Kaliraj (Mediterr. J. Math. 12: 647--665, 2015), are obtained.Comment: 11 pages, 2 figures. To appear in Rocky Mountain J. Mat

Two-dimensional confinement of critical U(1) gauge field in the presence of Fermi surface

The compact U(1) gauge field occurs in many fractionalized descriptions of low dimensional quantum magnetism and heavy fermion systems. In this respect a fundamental question about the gauge field is whether it is confined or not in the presence of Fermi surface. In this paper we show that the U(1) gauge field with a possible positive anomalous dimension in the presence of Fermi surface has to be in the confined state, although it is strongly coupled to abundant gapless fermionic excitations near the Fermi surface in two spatial dimensions. This means that some quantum spin liquids and/or fractionalized metallic states described in terms of this kind of gauge fields with positive anomalous dimensions are unstable to other possible symmetry-breaking states, as a result, they are not be appropriate candidates for ground states in related systems. The instability obtained shows some novel features of the quantum spin liquids and/or fractionalized metallic states in the presence of Fermi surface which have not been reported in the literature. The result could be useful for further study in the quantum spin liquids and many related slave-particle gauge theories in strongly correlated electron systems.Comment: 7 pages, no figures, revised and two appendix adde

Derivations of Normalized Mutual Information in Binary Classifications

This correspondence studies the basic problem of classifications - how to evaluate different classifiers. Although the conventional performance indexes, such as accuracy, are commonly used in classifier selection or evaluation, information-based criteria, such as mutual information, are becoming popular in feature/model selections. In this work, we propose to assess classifiers in terms of normalized mutual information (NI), which is novel and well defined in a compact range for classifier evaluation. We derive close-form relations of normalized mutual information with respect to accuracy, precision, and recall in binary classifications. By exploring the relations among them, we reveal that NI is actually a set of nonlinear functions, with a concordant power-exponent form, to each performance index. The relations can also be expressed with respect to precision and recall, or to false alarm and hitting rate (recall).Comment: 8 pages, 8 figures, and 2 table

Searching for a charged Higgs boson with both H±W∓ZH^{\pm}W^{\mp}Z and H±tbH^{\pm}tb couplings at the LHC

In certain new physics scenarios, a singly charged Higgs boson can couple to both fermions and $W^\pm Z$ at tree level. We develop new strategies beyond current experimental searches using $pp\to jjH^\pm$, $H^\pm \to tb$ at the Large Hadron Collider (LHC). With the effective $H^\pm W^\mp Z$ and $H^\pm tb$ couplings we perform a model-independent analysis at the collision energy $\sqrt{s}=13$~TeV with the integrated luminosity of $3~\text{ab}^{-1}$. We derive the discovery prospects and exclusion limits for the charged Higgs boson in the mass range from 200~GeV to 1~TeV. With $|F_{WZ}|,|A_t|\sim 0.5-1.0$ and $300~\text{GeV}\lesssim m_{H^\pm}\lesssim 400~\text{GeV}$, we point out that a discovery significance of $5\sigma$ can be achieved. The constraints and projected sensitivities are also discussed in a realistic model, i.e., the modified Georgi-Machacek model without custodial symmetry. Our proposed search would provide direct evidence for a charged Higgs boson $H^\pm$ that couples to $W^\pm Z$ and $tb$, which can have better sensitivity to the couplings of $H^\pm W^\mp Z$ and $H^\pm tb$ than current searches.Comment: match the published version in JHE