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.
13641910
The frequency separations of stellar p-modes
Aims. The purpose of this work is to investigate the characteristics of a new frequency separation of stellar p-modes. Methods. Frequency separations are deduced from the asymptotic formula of stellar p-modes. Then, using the theoretical adiabatic frequencies of stellar model, we compute the frequency separations. Results. A new separation sigma(l-1l+ 1)( n), which is similar to the scaled small separation d(ll+ 2)( n)/(2l + 3), is obtained from the asymptotic formula of stellar p-modes. The separations sigma(l-1l+ 1)( n) and d(ll+ 2)( n)/(2l+ 3) have the same order. And like the small separation, sigma(l)-(1l+ 1)( n) is mainly sensitive to the conditions in the stellar core. However, with the decrease in the central hydrogen abundance of stars, the separations sigma(02) and rho(13) deviate more and more from the scaled small separation. This characteristic could be used to extract the information on the central hydrogen abundance of stars.
119219756
Asteroseismic constraints on the OPAL opacity interpolation
The frequency difference between a model used only two-point interpolation of opacity and a model used piecewise linear interpolation of opacity is of the order of several microHertz at a certain stage, which is almost 10 times worse than the observational precision of p-modes of solar-like stars. Therefore, the two-point interpolation of opacity is unsuitable in modelling of solar-like stars with element diffusion.
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.
119569626
Parabose Squeezed Operator and Its Applications
By virtue of the parabose squeezed operator, propagator of a parabose parametric amplifier, explicit form of parabose squeezed number states and normalization factors of excitation states on a parabose squeezed vacuum atate are calculated in this letter, which generalize the relevant results from ordinary Bose statistics to parabose case.
16500187
Fermion masses and flavor mixing in supersymmetric SO(10) model
Abstract We study fermion masses and flavor mixing in a supersymmetric SO ( 10 ) model, where 10, 120 and 126 ¯ Higgs multiplets have Yukawa couplings with matter multiplets and give masses to quarks and leptons through the breaking chain of a Pati–Salam group. This brings about that, at the GUT energy scale, the lepton mass matrices are related to the quark ones via several breaking parameters, and the small neutrino masses arise from a Type II see-saw mechanism. When evolving renormalization group equations for the fermion mass matrices from the GUT scale to the electroweak scale, in a specific parameter scenario, we show that the model can elegantly accommodate all observed values of masses and mixing for the quarks and leptons, especially, it's predictions for the bi-large mixing in the leptonic sector are very well in agreement with the current neutrino experimental data.
17934543
Bosonization of Quantum Sine–Gordon Field with Boundary
Boundary operators and boundary ground states in sine–Gordon model with a fixed boundary condition are studied using bosonization and q-deformed oscillators. We also obtain the form-factors of this model.
14352659
The new extended left–right symmetric grand unified model with SO(3) family symmetry
Abstract We suggest a new left–right symmetric grand unified model by extending Pati–Salam group to contain an isospin SU ( 2 ) and a flavor SO ( 3 ) subgroup, where the superheavy fermions are introduced as a mirror to the low-energy standard model fermions. The model undergoes three steps to break to the SM by means of the specified Higgs multiplets. The model few parameters can elegantly accommodate whole mass spectra for all the particles at the electroweak scale, especially, two different flavor mixing for the quark and lepton sectors are reproduced in agreement with the current experimental data very well. The strong CP violation is excellently explained. The matter–antimatter asymmetry in the universe is successfully implemented through the B − L violating decays of the superheavy gauge bosons. The model also predicts that the lightest right-handed Majorana neutrino, whose mass is about several hundred GeVs and energy is about 10 16 GeV, is possibly a candidate for the dark matter.
11672433
Reanalysis the pentaquark $\Theta^+(1540)$ in the framework of QCD sum rules approach with direct instantons
In this article, we study the pentaquark state Θ+(1540) with a (scalar)diquark(pseudoscalar)diquark-antiquark type interpolating current in the framework of the QCD sum rules approach by including the contributions from the direct instantons. The numerical results indicate that the contributions from the direct instantons are very small and can be safely neglected. PACS : 12.38.Aw, 12.38.Lg, 12.39.Ba, 12.39.-x