Comment on "Valence QCD: Connecting QCD to the Quark Model"

I criticize certain conclusions about the physics of hadrons drawn from a "valence QCD" approximation to QCD.Comment: 12 pages, 8 figures; some minor improvements made to the tex

Contextual-based Image Inpainting: Infer, Match, and Translate

We study the task of image inpainting, which is to fill in the missing region of an incomplete image with plausible contents. To this end, we propose a learning-based approach to generate visually coherent completion given a high-resolution image with missing components. In order to overcome the difficulty to directly learn the distribution of high-dimensional image data, we divide the task into inference and translation as two separate steps and model each step with a deep neural network. We also use simple heuristics to guide the propagation of local textures from the boundary to the hole. We show that, by using such techniques, inpainting reduces to the problem of learning two image-feature translation functions in much smaller space and hence easier to train. We evaluate our method on several public datasets and show that we generate results of better visual quality than previous state-of-the-art methods.Comment: ECCV 2018 camera read

Far-infrared optical conductivity of CeCu2Si2

Journal ref.: J. Phys.: Condens. Matter 25, 065602 (2013): We investigated the optical reflectivity of the heavy-fermion metal CeCu2Si2 in the energy range 3 meV - 30 eV for temperatures between 4K - 300K. The results for the charge dynamics indicate a behavior that is expected for the formation of a coherent heavy quasiparticle state: Upon cooling the spectra of the optical conductivity indicate a narrowing of the coherent response. Below temperatures of 30 K a considerable suppression of conductivity evolves below a peak structure at 13 meV. We assign this gap-like feature to strong electron correlations due to the 4f-conduction electron hybridization.Comment: 7 pages, 3 figure

Glueball enhancements in p(gamma,VV)p through vector meson dominance

Double vector meson photoproduction, p(gamma, G -> VV)p, mediated by a scalar glueball G is investigated. Using vector meson dominance (VMD) and Regge/pomeron phenomenology, a measureable glueball enhancement is predicted in the invariant VV = rho rho and omega omega mass spectra. The scalar glueball is assumed to be the lightest physical state on the daughter pomeron trajectory governing diffractive vector meson photoproduction. In addition to cross sections, calculations for hadronic and electromagnetic glueball decays, G -> V V' (V,V'= rho, omega, phi, gamma), and gamma_v V -> G transition form factors are presented based upon flavor universality, VMD and phenomenological couplings from phi photoproduction analyses. The predicted glueball decay widths are similar to an independent theoretical study. A novel signature for glueball detection is also discussed

Is the anomalous decay ratio of D_{sJ}(2632) due to isospin breaking?

Quark pair annihilation into gluons is suppressed at large momenta due to the asymptotic freedom. As a consequence, mass eigenvalues of heavy states should be almost diagonal with respect to up and down quark masses, thereby breaking isospin. We suggest the particle observed by the SELEX Collaboration, D_{sJ}(2632) to be to a good extent a [cd][dbar sbar] state, which would explain why its D^0 K^+ mode is anomalously suppressed with respect to D_s eta. Predictions for the rates of the yet unobserved modes D_s pi^0 and D^+ K^0 are given.Comment: 3 pages, 1 figur

Multichannel calculation for Ds* vector states and the Ds(2632) resonance

We study bound states below threshold and resonances above threshold in the D0-K+ and Ds-eta systems, using a many-coupled-channel model for non-exotic meson-meson scattering applied to states with the quantum numbers of c-sbar quark-antiquark vector mesons. We fit the ground state at 2.112 GeV, whence the lowest resonances in D0-K+ come out at 2.61, 2.72, 3.03, and 3.08 GeV. The resonance at 2.61 GeV acquires a width of about 8 MeV, while its partial P-wave cross section is up to six times larger in Ds-eta than in D0-K+, provided a mechanism accounting for Okubo-Zweig-Iizuka--forbidden decays is included. The latter finding is in agreement with the observations of the SELEX collaboration with respect to the recently reported DsJ(2632) resonance. Therefore, we conclude that the DsJ(2632) is most probably the first recurrence excitation of the Ds*(2112) meson.Comment: 11 pages, 6 figures; v2: Significant improvements for threshold behavior, and for the hadronic widths by including additional two-meson channels. Misprints in formulas correcte

Empirical Determination of Threshold Partial Wave Amplitudes in pp→ppωp p \to p p \omega

Using the model independent irreducible tensor approach to $\omega$ production in $pp$ collisions, we show theoretically that, it is advantageous to measure experimentally the polarization of $\omega$, in addition to the proposed experimental study employing a polarized beam and a polarized target.Comment: 6 pages, 1 Table, Latex-2

Weak mixing angle at low energies

We determine the weak mixing angle in the MS-bar scheme at energy scales relevant for present and future low energy electroweak measurements. We relate the renormalization group evolution of the weak mixing angle to the corresponding evolution of the QED coupling and include higher-order terms in alpha_s and alpha that had not been treated in previous analyses. We also up-date the analysis of non-perturbative hadronic contributions and argue that the associated uncertainty is small compared to anticipated experimental errors. The resulting value of the low-energy weak mixing angle is sin^2 theta_W (0) = 0.23867 +- 0.00016.Comment: 21 pages; 1 figure and some references added, some changes in text; final version as publishe

Gas bulk motion in the Perseus cluster measured with SUZAKU

We present the results from Suzaku observations of the Perseus galaxy cluster, which is relatively close, the brightest in the X-ray sky and a relaxed object with a cool core. A number of exposures of central regions and offset pointing with the X-ray Imaging Spectrometer cover a region within radii of 20'-30'. The central data are used to evaluate the instrumental energy-scale calibration with accuracy confirmed to within around 300 km/s, by the spatial and temporal variation of the instruments. These deep and well-calibrated data are used to measure X-ray redshifts of the intracluster medium. A hint of gas bulk motion, with radial velocity of about -(150-300) km/s, relative to the main system was found at 2-4 arcmin (45-90kpc) west of the cluster center, where an X-ray excess and a cold front were found previously. No other velocity structure was discovered. Over spatial scales of 50-100kpc and within 200kpc radii of the center, the gas-radial-velocity variation is below 300 km/s, while over scales of 400 kpc within 600 kpc radii, the variation is below 600 km/s. These X-ray redshift distributions are compared spatially with those of optical member galaxies for the first time in galaxy clusters. Based on X-ray line widths gas turbulent velocities within these regions are also constrained within 1000-3000 km/s. These results of gas dynamics in the core and larger scales in association with cluster merger activities are discussed and future potential of high-energy resolution spectroscopy with ASTRO-H is considered.Comment: Accepted to Ap

Temperature- and Magnetic-Field-Dependent Optical Properties of Heavy Quasiparticles in YbIr2Si2

We report the temperature- and magnetic-field-dependent optical conductivity spectra of the heavy electron metal YbIr$_2$Si$_2$. Upon cooling below the Kondo temperature ($T_{\rm K}$), we observed a typical charge dynamics that is expected for a formation of a coherent heavy quasiparticle state. We obtained a good fitting of the Drude weight of the heavy quasiparticles by applying a modified Drude formula with a photon energy dependence of the quasiparticle scattering rate that shows a similar power-law behavior as the temperature dependence of the electrical resistivity. By applying a magnetic field of 6T below $T_{\rm K}$, we found a weakening of the effective dynamical mass enhancement by about 12% in agreement with the expected decrease of the $4f$-conduction electron hybridization on magnetic field.Comment: 5 pages, 4 figures. to be published in Journal of the Physical Society of Japan Vol. 79 (2010) No. 1