118561506
A Model of Fermion Flavor and Leptogenesis and Cold Dark Matter
I suggest a new particle model to integrate the fermion flavor, the TeV scale Leptogenesis and cold dark matter. The model has a local gauge symmetry $U(1)_{B-L}$ at the TeV scale and a flavor family symmetry SO(3), in addition, it also contains the fourth generation fermions in which including a cold dark matter neutrino. The model can simultaneously account for the fermion masses and flavor mixings, and the baryon asymmetry and cold dark matter. It not only excellently fits all the current experimental data, but also predicts some new results which are promising to be test in future experiments.
14097903
Magnetic moment of the pentaquark Θ+(1540) as diquark-diquark-antiquark state with QCD sum rules
Abstract.In this article, we study the magnetic moment of the pentaquark state Θ+(1540) as a diquark-diquark-antiquark ($[ud][ud]\bar{s}$) state with the QCD sum rules in an external weak electromagnetic field (EFSR) and the light-cone QCD sum rules (LCSR) respectively. The numerical results indicate that the magnetic moment is about $\mu_{\Theta^ + } = -(0.11\pm 0.02)\mu_N$ for the EFSR and $\mu_{\Theta^ + }\approx-(0.1$-$0.5)\mu_N$ for the LCSR. As the values obtained from the EFSR are more stable than the corresponding ones from the LCSR, $\mu_{\Theta^ + } = -(0.11\pm 0.02)\mu_N$ is more reliable.
260040
CP violation in chargino decays in the MSSM
In the minimal supersymmetric standard model (MSSM) with complex parameters, supersymmetric loop effects can lead to $\mathrm{CP}$ violation. We calculate the rate asymmetries of decays of charginos into the lightest neutralino and a W boson on the basis of the most important loop contributions in the third generation squark sector. It turns out that the $\mathrm{CP}$ violating asymmetries can be a few percent in typical regions of the parameter space of the MSSM. These processes would provide very promising channels for probing $\mathrm{CP}$ violation in the MSSM at future high-energy colliders.
16260034
Axial form-factor and induced pseudoscalar form-factor of the nucleons
We calculate the axial and the induced pseudoscalar form-factors GA(t=-Q2) and GP(t=-Q2) of the nucleons in the framework of the light-cone QCD sum-rules approach up to twist-6 three valence quark light-cone distribution amplitudes, and observe that the form-factors GA(t=-Q2) and GP(t=-Q2) at intermediate and large momentum transfers with Q2>2 GeV2 have significant contributions from the end-point (soft) terms. The numerical values for the axial form-factor GA(t=-Q2) are compatible with the experimental data and theoretical calculations; for example, the chiral quark models and lattice QCD. The numerical values for the induced pseudoscalar form-factor GP(t=-Q2) are compatible with the calculation from the Bethe–Salpeter equation.
119409718
Decay constants of the pseudoscalar mesons in the framework of the coupled Schwinger–Dyson equation and Bethe–Salpeter equation
Abstract In this article, we investigate the structures of the pseudoscalar mesons ( π , K , D , D s , B and B s ) in the framework of the coupled rainbow Schwinger–Dyson equation and ladder Bethe–Salpeter equation with the confining effective potential (infrared modified flat bottom potential). The Schwinger–Dyson functions for the u , d and s quarks are greatly renormalized at small momentum region and the curves are steep at about q 2 = 1 GeV 2 which indicates an explicitly dynamical symmetry breaking. The Euclidean time Fourier transformed quark propagators have no mass poles in the time-like region which naturally implements confinement. As for the c and b quarks, the current masses are very large, the renormalization are more tender, however, mass poles in the time-like region are also absent. The Bethe–Salpeter wavefunctions for those mesons have the same type (Gaussian type) momentum dependence and center around small momentum which indicate that the bound states exist in the infrared region. The decay constants for those pseudoscalar mesons are compatible with the values of experimental extractions and theoretical calculations, such as lattice simulations and QCD sum rules.
255344
Scalar form-factor of the proton with light-cone QCD sum rules
We calculate the scalar form factor of the proton in the framework of the light-cone QCD sum rules approach with the three valence quark light-cone distribution amplitudes up to twist-6 and observe the scalar form factor {sigma}(t=-Q{sup 2}) at intermediate and large momentum transfers Q{sup 2}>2 GeV{sup 2} has significant contributions from the end point (or soft) terms. The numerical values for the {sigma}(t=-Q{sup 2}) are compatible with the calculations from the chiral quark model and lattice QCD at the region Q{sup 2}>2 GeV{sup 2}.
14483058
Solar models with revised abundances and opacities
Using reconstructed opacities, we construct solar models with low heavy-element abundance. Rotational mixing and enhanced diffusion of helium and heavy elements are used to reconcile the recently observed abundances with helioseismology. The sound speed and density of models in which the relative and absolute diffusion coefficients for helium and heavy elements have been increased agree with seismically inferred values at better than the 0.005 and 0.02 fractional levels, respectively. However, the surface helium abundance of the enhanced diffusion model is too low. The low-helium problem in the enhanced diffusion model can be solved to a great extent by rotational mixing. The surface helium and the convection zone depth of rotating model M04R3, which has a surface Z of 0.0154, agree with the seismic results at the levels of 1 sigma and 3 sigma, respectively. M04R3 is almost as good as the standard model M98. Some discrepancies between the models constructed in accord with the new element abundances and seismic constraints can be solved individually, but it seems difficult to resolve them as a whole.
119131972
Determinant representations of scalar products for the open XXZ chain with non-diagonal boundary terms
The determinant representation of the scalar products of the Bethe states of the open XXZ spin chain with non-diagonal boundary terms is studied. Using the vertex-face correspondence, we transfer the problem into the corresponding trigonometric solid-on-solid (SOS) model with diagonal boundary terms. With the help of the Drinfeld twist or factorizing F-matrix, we obtain the determinant representation of the scalar products of the Bethe states of the associated SOS model. By taking the on shell limit, we obtain the determinant representations (or Gaudin formula) of the norms of the Bethe states.
118821038
Completeness and Bethe root distribution of the spin-1/2 Heisenberg chain with arbitrary boundary fields
Recently, the XXX spin chain with arbitrary boundary fields was successfully solved [1] via the off-diagonal Bethe ansatz method [2]. The correctness and the completeness of this solution were numerically verified by Nepomechie for one choice of the parameterizations [3]. In this paper, we discuss further the completeness of another parameterization of the Bethe ansatz equations and its reduction to the parallel boundary field case. The numerical results show that when the relative angle between the boundary fields turns to zero, both the T-Q relations and the Bethe ansatz equations are reduced to the ones obtained by the conventional Bethe ansatz methods. This allows us to establish a one-to-one correspondence between the Bethe roots of the unparallel boundary field case and those of the parallel boundary field case. In the thermodynamic limit, those two sets of Bethe roots tend to the same and the contribution of the relative angle to the energy is in the order of 1/N.
11787531
The dynamical twisting and nondynamical r-matrix structure of the elliptic Ruijsenaars–Schneider model
From the dynamical twisting of the classical r-matrix, we obtain a new Lax operator for the elliptic Ruijsenaars–Schneider model (cf. Ruijsenaars). The corresponding r-matrix is shown to be the classical Zn-symmetric elliptic r-matrix, which is the same as that obtained in the study of the nonrelativistic version—the An−1 Calogero–Moser model.
17301039
The Color Excesses of Type Ia Supernovae from Single-Degenerate Channel Model
Single Degenerate model is the most widely accepted progenitor model of type Ia supernovae (SNe Ia), in which a carbon-oxygen white dwarf (CO WD) accretes hydrogen-rich material from a main sequence or a slightly evolved star (WD +MS) to increase its mass, and explodes when its mass approaches the Chandrasekhar mass limit. During the mass transfer phase between the two components, an optically thick wind may occur and the material lost as the wind may exist as circumstellar material (CSM). Searching the CSM around progenitor star is helpful to discriminate different progenitor models of SNe Ia. Meanwhile, the CSM is a source of color excess.The purpose of this paper is to study the color excess produced from the single-degenerate progenitor model with optically thick wind, and reproduce the distribution o f color excesses of SNe Ia. Meng et al. (2009) systemically carried out binary evolution calculation of the WD +MS systems for various metallicities and showed the parameters of the systems before Roche lobe overflow and at the moment of supernova explosion in Meng & Yang (2009). With the results of Meng et al. (2009), we calculate the color excesses of SNe Ia at maximum light via a simple analytic method.We reproduces the distribution of color excesses of SNe Ia by our binary population synthesis approach if the velocity of the optically thick wind is taken to be of order of magnitude of 10 km s −1 . However, if the wind velocity is larger than 100 km s −1 , the reproduction is bad.