Goodness-of-Fit Tests for Symmetric Stable Distributions -- Empirical Characteristic Function Approach

We consider goodness-of-fit tests of symmetric stable distributions based on weighted integrals of the squared distance between the empirical characteristic function of the standardized data and the characteristic function of the standard symmetric stable distribution with the characteristic exponent $\alpha$ estimated from the data. We treat $\alpha$ as an unknown parameter, but for theoretical simplicity we also consider the case that $\alpha$ is fixed. For estimation of parameters and the standardization of data we use maximum likelihood estimator (MLE) and an equivariant integrated squared error estimator (EISE) which minimizes the weighted integral. We derive the asymptotic covariance function of the characteristic function process with parameters estimated by MLE and EISE. For the case of MLE, the eigenvalues of the covariance function are numerically evaluated and asymptotic distribution of the test statistic is obtained using complex integration. Simulation studies show that the asymptotic distribution of the test statistics is very accurate. We also present a formula of the asymptotic covariance function of the characteristic function process with parameters estimated by an efficient estimator for general distributions

Galactic-Center Hyper-Shell Model for the North Polar Spurs

The bipolar-hyper shell (BHS) model for the North Polar Spurs (NPS-E, -W, and Loop I) and counter southern spurs (SPS-E and -W) is revisited based on numerical hydrodynamical simulations. Propagations of shock waves produced by energetic explosive events in the Galactic Center are examined. Distributions of soft X-ray brightness on the sky at 0.25, 0.7, and 1.5 keV in a +/-50 deg x +/-50 deg region around the Galactic Center are modeled by thermal emission from high-temperature plasma in the shock-compressed shell considering shadowing by the interstellar HI and H2 gases. The result is compared with the ROSAT wide field X-ray images in R2, 4 and 6 bands. The NPS and southern spurs are well reproduced by the simulation as shadowed dumbbell-shaped shock waves. We discuss the origin and energetics of the event in relation to the starburst and/or AGN activities in the Galactic Center. [ High resolution pdf is available at http://www.ioa.s.u-tokyo.ac.jp/~sofue/htdocs/2016bhs/ ]Comment: 13 pages, 20 figures; To appear in MNRA

Quark-Hadron Duality and Parity Violating Asymmetry of Electroweak Reactions in the Delta Region

A dynamical model of electroweak pion production reactions in the Delta(1232) region has been extended to include the neutral current contributions for examining the local Quark-Hadron Duality in neutrino-induced reactions and for investigating how the axial N-Delta form factor can be determined by the parity violating asymmetry of N(\vec{e},e') reactions. We first show that the recent data of (e,e') structure functions F_1 and F_2, which exhibit the Quark-Hadron Duality, are in good agreement with our predictions. For possible future experimental tests, we then predict that the structure functions F_1, F_2, and F_3 for (\nu,e) and (\nu,\nu') processes also show the similar Quark-Hadron Duality. The spin dependent structure functions g_1 and g_2 of (e,e') have also been calculated from our model. It is found that the local Quark-Hadron Duality is not seen in the calculated g_1 and g_2, while our results for g_1 and some polarization observables associated with the exclusive p(\vec{e},e' pi) and \vec{p}(\vec{e},e' pi) reactions are in reasonably good agreement with the recent data. In the investigation of parity violating asymmetry A of N(\vec{e},e') reactions, it is found that the non-resonant contribution is small at the Delta peak and a measurement of A can be used to distinguish two previously determined axial N-Delta transition form factors. The predicted asymmetry A are also compared with the Parton Model predictions for future experimental investigations of Quark-Hadron Duality.Comment: 28 pages, 19 figures v2; figures and references adde

Critical Behavior of J/psi across the Phase Transition from QCD sum rules

We study behavior of J/psi in hot gluonic matter using QCD sum rules. Taking into account temperature dependences of the gluon condensates extracted from lattice thermodynamics for the pure SU(3) system, we find that the mass and width of J/psi exhibit rapid change across the critical temperature.Comment: 5 pages, 3 figures. Poster contribution for Quark Matter 2008. To be published in the proceeding

Holographic Screening Length in a Hot Plasma of Two Sphere

We study the screening length of a quark-antiquark pair moving in a hot plasma living in two sphere $S^2$ manifold using AdS/CFT correspondence where the background metric is four dimensional Schwarzschild-AdS black hole. The geodesic solution of the string ends at the boundary is given by a stationary motion in the equatorial plane as such the separation length $L$ of quark-antiquark pair is parallel to the angular velocity $\omega$. The screening length and the bound energy are computed numerically using Mathematica. We find that the plots are bounded from below by some functions related to the momentum transfer $P_c$ of the drag force configuration. We compare the result by computing the screening length in the quark-antiquark reference frame where the gravity dual are "Boost-AdS" and Kerr-AdS black holes. Finding relations of the parameters of both black holes, we argue that the relation between mass parameters $M_{Sch}$ of the Schwarzschild-AdS black hole and $M_{Kerr}$ of the Kerr-AdS black hole in high temperature is given by $M_{Kerr}=M_{Sch}(1-a^2l^2)^{3/2}$, where $a$ is the angular momentum parameter.Comment: Major revision: title changed, adding authors, 13 pages, 8 figures, etc. Accepted for publication in European Physical Journal

Clear Experimental Signature of Charge-Orbital density wave in Nd1−x_{1-x}Ca1+x_{1+x}MnO4_{4}

Single Crystals of Nd$_{1-x}$Ca$_{1+x}$MnO$_{4}$ have been prepared by the travelling floating-zone method, and possible evidence of a charge -orbital density wave in this material presented earlier [PRB68,092405 (2003)] using High Resolution Electron Microscopy [HRTEM] and Electron Diffraction [ED]. In the current note we present direct evidence of charge-orbital ordering in this material using heat capacity measurements. Our heat capacity measurements indicate a clear transition consistent with prior observation. We find two main transitions, one at temperature $T_{_H}=310-314$ K, and other at $T_{_A}=143$ K. In addition, we may also conclude that there is a strong electron-phonon coupling in this material.Comment: 7 pages, 8 figure