123727874
Thermal Entanglement in Two-Qutrit Heisenberg XX Chain with Different Dzyaloshinskii—Moriya Interaction and Nonuniform Magnetic Field
The effects of the different Dzyaloshinskii—Moriya (DM) interaction on thermal entanglement of a two-qutrit Heisenberg XX spin chain in a nonuniform magnetic field are investigated. Our results imply that the x-component DM interaction plays a central role in enhancing quantum entanglement and it has a higher critical temperature than the z-component DM interaction. The entanglement can be tunable controlled by changing the multiple of the magnetic fields B1 and B2. Also we found that different DM interaction are competitive to each other in some conditions.
118810528
Nonparametric inference with applications to dark matter estimation in astronomy and degradation modeling in *reliability.
119021398
Internal Kinematics of the Fornax Dwarf Spheroidal Galaxy
We present new radial velocity results for 176 stars in the Fornax dwarf spheroidal galaxy, of which at least 156 are probable Fornax members. We combine with previously published data to obtain a radial velocity sample with 206 stars, of which at least 176 are probable Fornax members.We detect the hint of rotation about an axis near Fornax’s morphological minor axis, although the significance of the rotation signal in the galactic rest frame is sensitive to the adopted value of Fornax’s proper motion. Regardless, the observed stellar kinematics is dominated by randommotions, andwe do not find kinematic evidence of tidal disruption. The projected velocity dispersion profile of the binned data set remains flat over the sampled region, which reaches a maximum angular radius of 650. Single-component King models in which mass follows light fail to reproduce the observed flatness of the velocity dispersion profile. Two-component ( luminous plus dark matter) models can reproduce the data, provided that the dark component extends sufficiently beyond the luminous component and the central dark matter density is of the same order as the central luminous density. These requirements suggest a more massive, darker Fornax than standard core-fitting analyses have previously concluded, with M/LV over the sampled region reaching 10–40 times the M/LV of the luminous component. We also apply a nonparametric mass estimation technique, introduced in a companion paper. Although it is designed to operate on data sets containing velocities for >1000 stars, the estimation yields preliminary results suggesting M /LV 15 inside r < 1:5 kpc.
118862850
Mass spectrum and strong decays of isoscalar tensor mesons
In this work, we present a systematic study of the observed isoscalar tensor f(2) states. With the detailed analysis of the mass spectrum and calculation of the f(2) two-body strong decays, we extract information from their underlying structures and try to categorize them into the conventional tensor meson family [n(3)P(2) (n = 1, 2, 3, 4) and m(3)F(2) (m = 1, 2)]. We also give predictions for other decay modes of these tensor mesons, which are useful for further experimental investigations.
119210042
Non-strange partner of strangeonium-like state Y(2175)
Inspired by the observed Y(2175) state, we predict its nonstrange partner Y(1915), which has a resonance structure with mass around 1915 MeV and width about 317-354 MeV. Experimental search for Y(1915) is proposed by analyzing the omega f(0)(980) or omega pi pi invariant mass spectrum of the e(+)e(-) -> omega f(0)(980), omega pi pi, and J/psi -> eta omega f(0)(980) processes, which are accessible at Belle, BABAR, BESIII and forthcoming BelleII. Considering similarity between two families, the comparison of the mass spectra of omega and phi families can provide important information on the 1D state of phi family, phi(1910), which has a very broad resonance structure with mass around 1910 MeV regarded as the strangeonium partner of omega(1650). This also answers the question why the 1D state phi(1910) is still missing in experiment. This is supported by our former study on the properties of Y(2175), which explains Y(2175) as the 2D strangeonium because our theoretical total width is comparable with the Belle data.
54577144
Research on mechanical stability for third-generation light source
The mechanical stability, a key problem for the 3rd synchrotron light source, is essential for the electron beam performance. This paper analyzes the influences of the first eigenfrequency and Q value on the mechanical stability. Then the research on the improvement of the mechanical stability for the magnet girder assemblies (MGAs) and the dipole concrete assemblies (DCAs), both of which are the main parts of the Shanghai Synchrotron Radiation Faculty (SSRF), is performed. The measurement result shows that the mechanical stability is improved obviously for the MGAs by using the auxiliary supports and for the DCAs by using polymer-modification concrete instead of common concrete. The paper can give some guidance to the mechanical design of the 3rd generation light sources.
119116897
High-energy jet quenching in weakly coupled quark-gluon plasmas
q is the average squared transverse momentum transfer per unit length to a high-energy particle traversing a QCD medium such as a quark-gluon plasma. We find the (UV-regulated) value of q to leading order in the weak coupling limit, {alpha}{sub s}(T)<<1. We then use this value to generalize previous analytic results on the gluon bremsstrahlung and pair production rates for massless high-energy particles in a weakly coupled quark-gluon plasma, at next-to-leading logarithmic order.
118605539
Stopping distance for high energy jets in weakly coupled quark-gluon plasmas
We derive a simple formula for the stopping distance for a high-energy quark traveling through a weakly coupled quark-gluon plasma. The result is given to next-to-leading order in an expansion in inverse logarithms ln(E/T), where T is the temperature of the plasma. We also define a stopping distance for gluons and give a leading-log result. Discussion of stopping distance has a theoretical advantage over discussion of energy loss rates in that stopping distances can be generalized to the case of strong coupling, where one may not speak of individual partons.
8413154
A Cosmology-Independent Calibration of Gamma-Ray Burst Luminosity Relations and the Hubble Diagram
An important concern in the application of gamma-ray bursts (GRBs) to cosmology is that the calibration of GRB luminosity/energy relations depends on the cosmological model, due to the lack of a sufficient low-redshift GRB sample. In this paper, we present a new method to calibrate GRB relations in a cosmology-independent way. Since objects at the same redshift should have the same luminosity distance, and since the distance moduli of Type Ia supernovae (SNe Ia) obtained directly from observations are completely cosmology independent, we obtain the distance modulus of a GRB at a given redshift by interpolating from the Hubble diagram of SNe Ia. Then we calibrate seven GRB relations without assuming a particular cosmological model and construct a GRB Hubble diagram to constrain cosmological parameters. From the 42 GRBs at 1: 4 < z <= 6: 6, we obtain Omega(M) = 0.25(-0.05)(+0.04), Omega(Lambda) = 0.75(-0.04)(+0.05) for the flat Lambda CDM model, and for the dark energy model with a constant equation of state w(0) = -1.05(-0.40)(+0.27), which is consistent with the concordance model in a 1 sigma confidence region.
119125316
Second order hydrodynamic coefficients from 3-point stress tensor correlators via AdS/CFT
We study second order relativistic viscous hydrodynamics in 4-dimensional conformal field theories. We derive Kubo-type relations for second order hydrodynamic coefficients in terms of 3-point stress tensor retarded correlators. For $ \mathcal{N} = 4 $ super Yang-Mills theory at strong coupling and at finite temperature we compute these stress tensor 3-point correlators, using AdS/CFT, by evaluating real-time cubic Witten diagrams in the AdS-Schwarzschild background. The small momentum expansion of the 3-point correlators in terms of first and second order hydrodynamic coefficients is matched with the AdS result. We arrive at the same expressions for the hydrodynamic coefficients which multiply terms quadratic in the shear and vorticity tensors in the hydrodynamic expansion of the stress tensor as did Bhattacharyya, Hubeny, Minwalla and Rangamani [1]. Our method extends the results of Baier et al [2], and allows for a unified treatment of hydrodynamic coefficients, which are extracted from 2-, and now, 3-point retarded stress tensor correlators in the AdS-Schwarzschild background.