Photoproduction of Λ(1405)\Lambda(1405) with the two-pole structure

We investigate the $\Lambda(1405,1/2^-)\equiv\Lambda^*$ photoproduction off the proton target, i.e. $\gamma p\to K^+\Lambda^*$, considering explicitly its two-pole structure, the higher ($\Lambda^*_H:\,1430\,\mathrm{MeV}$) and lower ($\Lambda^*_L:\,1390\,\mathrm{MeV}$) mass-pole contributions, suggested by the chiral-unitary model (ChUM) approaches. For this purpose, we construct a two-body process model, which mimics the Dalitz process, $\gamma p\to K^+\pi\Sigma$, assuming that the mass of $\Lambda^*$ as the invariant mass of $\pi$ and $\Sigma$, i.e. $M_{\Lambda^*}\sim M_{\pi\Sigma}$. We employ the effective Lagrangian method with the tree-level Born approximation, using the gauge-invariant prescription for the phenomenological form factors. We provide the numerical results for the energy and angular dependences, $\pi$-$\Sigma$ invariant-mass distribution, and so on. It turns out that the model parameters determined from ChUM reproduce the experimental data qualitatively well, supporting the two-pole structure. Moreover, the nucleon resonance contribution near the threshold plays an important role to describe the data.Comment: 13 pages, 25 figure

Is Dust Cloud around λ\lambda Orionis a Ring or a Shell, or Both?

The dust cloud around $\lambda$ Orionis is observed to be circularly symmetric with a large angular extent ($\approx$ 8 degrees). However, whether the three-dimensional (3D) structure of the cloud is shell- or ring-like has not yet been fully resolved. We study the 3D structure using a new approach that combines a 3D Monte Carlo radiative transfer model for ultraviolet (UV) scattered light and an inverse Abel transform, which gives a detailed 3D radial density profile from a two-dimensional column density map of a spherically symmetric cloud. By comparing the radiative transfer models for a spherical shell cloud and that for a ring cloud, we find that only the shell model can reproduce the radial profile of the scattered UV light, observed using the S2/68 UV observation, suggesting a dust shell structure. However, the inverse Abel transform applied to the column density data from the Pan-STARRS1 dust reddening map results in negative values at a certain radius range of the density profile, indicating the existence of additional, non-spherical clouds near the nebular boundary. The additional cloud component is assumed to be of toroidal ring shape; we subtracted from the column density to obtain a positive, radial density profile using the inverse Abel transform. The resulting density structure, composed of a toroidal ring and a spherical shell, is also found to give a good fit to the UV scattered light profile. We therefore conclude that the cloud around $\lambda$ Ori is composed of both ring and shell structures.Comment: 8 pages, 8 figures, accepted for publication in Ap

Far-ultraviolet study of the local supershell GSH 006-15+7

We have analyzed the archival data of FUV observations for the region of GSH 006-15+7, a large shell-like structure discovered by Moss et al. (2012) from the H I velocity maps. FUV emission is seen to be enhanced in the lower supershell region. The FUV emission is considered to come mainly from the scattering of interstellar photons by dust grains. A corresponding Monte Carlo simulation indicates that the distance to the supershell is 1300 +- 800 pc, which is similar to the previous estimation of 1500 +- 500 pc based on kinematic considerations. The spectrum at lower Galactic latitudes of the supershell exhibits molecular hydrogen fluorescence lines; a simulation model for this candidate photodissociation region (PDR) yields an H_2 column density of N(H_2) = 10^{18.0-20.0} cm^{-2} with a rather high total hydrogen density of n_H ~ 30 cm^{-3}.Comment: 7 pages, 5 figure

Ensemble in phase space: statistical formalism of quantum mechanics

We present an alternative formalism of quantum mechanics tailored to statistical ensemble in phase space. The purpose of our work is to show that it is possible to establish an alternative autonomous formalism of quantum mechanics in phase space using statistical methodology. The adopted perspective leads to obtaining within the framework of its theory the master quantum-mechanical equation without recourse to the other formalisms of quantum mechanics, and gives the idea of operators pertaining to dynamical quantities. The derivation of this equation starts with the ensemble in phase space. We have explained with the help of this equation the structure of quantum mechanics in phase space and the approximation to the Schrodinger equation. Furthermore, we have shown that this formalism provides reasonable results of quantization by dealing with some simple cases, which confirm the validity of this formalism. In particular, we have demonstrated that this formalism can easily give the relativistic wave equation without treating the problem of linearizing the Hamiltonian operator by making the most of the point that the master equation is a first-order partial differential equation with respect to time, position and momentum variables, and makes use of the phase velocity. The ultimate outcome this formalism produces is that primary and general matters of quantum mechanics can be studied reasonably within the framework of statistical mechanics.Comment: 19 page

Self-consistent one-electron equation including exchange and correlation in terms of equivalent function and phase norm: calculation for ground and excited states in a unified way

We present an alternative one-electron equation for resolving many-electron problem to one-electron approximation and including the exchange and correlation effects in an analytical way, thereby fulfilling the requirements for ab initio calculation. To derive one-electron equation, we accept a new notion of equivalent function suggestive of the pseudo wavefunction. As a result, we reduce many-electron equation to one-electron including the exchange effect in an analytical method. Moreover we accept the notion of phase norm for two electrons to resolve the electronic correlation problem. The phase norm is used to specify the electron-approachable limit between particles. We take into consideration the electronic correlation with the help of a correlation-hole function in terms of the phase norm, by which multiplying the integrand of the operator term representing the interaction between electrons. Using the phase norm leads to analytical consideration of the electronic correlation without employing in a factitious way the additional term pertaining to correlation, so it embodies the physical essence of electronic correlation. The derived equation becomes an one-electron equation which does not include an additional term pertaining to the exchange and correlation, but takes into consideration the exchange and correlation effects in a rigorous ab initio way.Comment: 12 page

Global distribution of far-ultraviolet emissions from highly ionized gas in the Milky Way

We present all-sky maps of two major FUV cooling lines, C IV and O VI, of highly ionized gas to investigate the nature of the transition-temperature gas. From the extinction-corrected line intensities of C IV and O VI, we calculated the gas temperature and the emission measure of the transition-temperature gas assuming isothermal plasma in the collisional ionization equilibrium. The gas temperature was found to be more or less uniform throughout the Galaxy with a value of (1.89 $\pm$ 0.06) $\times$ $10^5$ K. The emission measure of the transition-temperature gas is described well by a disk-like model in which the scale height of the electron density is $z_0=6_{-2}^{+3}$ kpc. The total mass of the transition-temperature gas is estimated to be approximately $6.4_{-2.8}^{+5.2}\times10^9 M_{\bigodot}$. We also calculated the volume-filling fraction of the transition-temperature gas, which was estimated to be $f=0.26\pm0.09$, and varies from $f\sim0.37$ in the inner Galaxy to $f\sim0.18$ in the outer Galaxy. The spatial distribution of C IV and O VI cannot be explained by a simple supernova remnant model or a three-phase model. The combined effects of supernova remnants and turbulent mixing layers can explain the intensity ratio of C IV and O VI. Thermal conduction front models and high-velocity cloud models are also consistent with our observation.Comment: 20 pages, 16 figures, Accepted to the Astrophysical Journal Supplement Serie

Far-ultraviolet fluorescent molecular hydrogen emission map of the Milky Way Galaxy

We present the far-ultraviolet (FUV) fluorescent molecular hydrogen (H_2) emission map of the Milky Way Galaxy obtained with FIMS/SPEAR covering ~76% of the sky. The extinction-corrected intensity of the fluorescent H_2 emission has a strong linear correlation with the well-known tracers of the cold interstellar medium (ISM), including color excess E(B-V), neutral hydrogen column density N(H I), and H_alpha emission. The all-sky H_2 column density map was also obtained using a simple photodissociation region model and interstellar radiation fields derived from UV star catalogs. We estimated the fraction of H2 (f_H2) and the gas-to-dust ratio (GDR) of the diffuse ISM. The f_H2 gradually increases from <1% at optically thin regions where E(B-V) < 0.1 to ~50% for E(B-V) = 3. The estimated GDR is ~5.1 x 10^21 atoms cm^-2 mag^-1, in agreement with the standard value of 5.8 x 10^21 atoms cm^-2 mag^-1.Comment: 24 pages, 15 figures, This is accepted for publication in ApJS at July 16, 201

A Study of an Modeling Method of T-S fuzzy System Based on Moving Fuzzy Reasoning and Its Application

To improve the effectiveness of the fuzzy identification, a structure identification method based on moving rate is proposed for T-S fuzzy model. The proposed method is called "T-S modeling (or T-S fuzzy identification method) based on moving rate". First, to improve the shortcomings of existing fuzzy reasoning methods based on matching degree, the moving rates for s-type, z-type and trapezoidal membership functions of T-S fuzzy model were defined. Then, the differences between proposed moving rate and existing matching degree were explained. Next, the identification method based on moving rate is proposed for T-S model. Finally, the proposed identification method is applied to the fuzzy modeling for the precipitation forecast and security situation prediction. Test results show that the proposed method significantly improves the effectiveness of fuzzy identification.Comment: 24 pages, 11 figure

Evolution of popularity in given names

An individual's identity in a human society is specified by his or her name. Differently from family names, usually inherited from fathers, a given name for a child is often chosen at the parents' disposal. However, their decision cannot be made in a vacuum but affected by social conventions and trends. Furthermore, such social pressure changes in time, as new names gain popularity while some other names are gradually forgotten. In this paper, we investigate how popularity of given names has evolved over the last century by using datasets collected in Korea, the province of Quebec in Canada, and the United States. In each of these countries, the average popularity of given names exhibits typical patterns of rise and fall with a time scale of about one generation. We also observe that notable changes of diversity in given names signal major social changes.Comment: 16 pages, 5 figures, 2 table

Comparison of the extraplanar Hα\alpha and UV emissions in the halos of nearby edge-on spiral galaxies

We compare vertical profiles of the extraplanar H$\alpha$ emission to those of the UV emission for 38 nearby edge-on late-type galaxies. It is found that detection of the "diffuse" extraplanar dust (eDust), traced by the vertically extended, scattered UV starlight, always coincides with the presence of the extraplanar H$\alpha$ emission. A strong correlation between the scale heights of the extraplanar H$\alpha$ and UV emissions is also found; the scale height at H$\alpha$ is found to be $\sim0.74$ of the scale height at FUV. Our results may indicate the multiphase nature of the diffuse ionized gas and dust in the galactic halos. The existence of eDust in galaxies where the extraplanar H$\alpha$ emission is detected suggests that a larger portion of the extraplanar H$\alpha$ emission than that predicted in previous studies may be caused by H$\alpha$ photons that originate from H II regions in the galactic plane and are subsequently scattered by the eDust. This possibility raise a in studying the eDIG. We also find that the scale heights of the extraplanar emissions normalized to the galaxy size correlate well with the star formation rate surface density of the galaxies. The properties of eDust in our galaxies is on a continuation line of that found through previous observations of the extraplanar polycyclic aromatic hydrocarbons emission in more active galaxies known to have galactic winds.Comment: 25 pages; 6 figures; It was accepted for publication in The Astrophysical Journal at June 7, 201