β-delayed proton decays near the proton drip line

Simply speaking, the drip line is the margin in chart of the nuclides where the nu-clides with the lower limits of detectable lifetime survive. The N/Z ratios of the nuclides on the drip line are extreme. Synthesis of the nuclei near the drip line and study of their exotic decays deal with the physics under extreme conditions, and therefore become one of the frontiers in nuclear physics today. The rare-earth nuclei near the proton drip line have been predicted to be highly deformed[1]. They a…     

Understanding the proton spin “puzzle” with a new “minimal” quark model

We investigate the spin structure of the nucleon in an extended Jaffe-Lipkin quark model. In addition to the conventional 3q structure, different (3q)(Q ) admixtures in the nucleon wave function are also taken into account. The contributions to the nucleon spin from various components of the nucleon wave function are discussed. The effect due to the Melosh-Wigner rotation is also studied. It is shown that the Jaffe-Lipkin term is only important when antiquarks are negatively polarized. We arrive at a new “minimal” quark model, which is close to the naive quark model, in order to understand the proton spin “puzzle”. Received: 4 November 2000 / Accepted: 23 October 2001     

Yield improvement for displays’ color filters surface by establishing a precision reclaim-module

An effective surface micromachining process for yield improvement was developed using microelectromechanical etching as a precision reclaim-module for indium tin oxide (ITO) thin-film nanostructures from the displays’ color filter surface of thin film transistor liquid crystal displays (TFT-LCDs). The low yield of ITO thin-film deposition is an important factor in optoelectronic semiconductor production. By establishing a recycling process using the ultra-precise removal of thin-film nanostructures, the optoelectronic semiconductor industry can effectively recycle defective products, minimizing both production costs and pollution. For the etching-process, an adequate gap-width between the negative-electrode and the ITO surface, a high flow velocity or a higher working temperature of the electrolyte, results in a higher removal rate for ITO thin-films. Also, adequate feed rate of the workpiece (displays’ color filter) combined with enough electrical power produces a fast removal rate. Pulsed direct current can improve the effect of dregs discharge and is advantageous to associate with the fast feed rate of the workpiece, but it raises the current rating. A smaller edge radius and a small width of the negative-electrode provide a larger discharge space and better etching effect. Microelectromechanical etching requires only a short period of time to remove the ITO thin-film easily and cleanly.     

Using color photometry to search for the solar corona “reddening” effect

The problems of searching for the solar corona reddening effect are analyzed. A new method is proposed for quantitative color photometry using a color film with significantly reduced sensitivity in the green spectral region. The results of the photometry of the solar corona slides obtained during the total solar eclipse of November 3, 1994 are presented. From the coronal intensity dependences on the distance in the red ( _eff=660nm) and blue ( _eff=440nm) spectral regions for a helmet-shaped streamer (P=70°)and in the region of reduced brightness (P=160°)the reddening effect was not detected up to a distance of (3.5–4)R .Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 39, No. 10, pp. 1287–1291, October, 1996.This work was supported in part by the Russian Foundation for Fundamental Research under Grant No. 93-02-2876 and under Grants No. CNPq 452339/94-4 (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) and FINEP Ref. 0104194 (Financiadora de Estudos e Projectos) on the Brazil side.     

Design of guided mode resonant filters for authentication applications through azimuthal angles varying

Guided mode resonant filters(GMRFs)for authentication application with low sideband reflection at 0°and 90°azimuthal angles were designed.Using rigorous coupled-wave analysis,the diffractive character- isties of this kind device with different illumination angles,groove depths,and thicknesses of cover SiO_2 layer were investigated.The structure of GMRF which satisfies the requirements for authentication appli- cations was obtained.Illuminated at 30°for a definite polarization mode,the filter presents symmetrical reflectance shape,low sideband reflectance,two separate reflectance peaks,and definite full-width at half- maximum(FWHM)at 0°and 90°azimuthal angles.     

Does proton decay follow the exponential law?

Tetrads cause the breakdown of symmetry in gravitational theories. Their vacuum expected values reduce the symmetry of the vacuum from that of the action to what is global Poincaré invariance at ordinary distances. Gravitational theories can be written in terms of rescaled fields in such a way that the Planck mass never appears. The rescaled fields are dimensionless, except for gauge fields and tetrads, both of which acquire the dimension of mass. The empirical distribution of energy throughout spacetime causes the tetrads to assume vacuum expected values of the order of the Planck mass,m _p . Thus the gravitational constant,G=hc/m _p ² , may be viewed not as a fundamental constant, but as a mass scale that is dynamically determined by the large-scale structure of the universe. Generalized tetrads may also break internal symmetries.     

Measurement of the beam asymmetry in η photoproduction off the proton

The beam asymmetry, Σ , was measured at ELSA in the reaction p → ηp using linearly polarised tagged photon beams, produced by coherent bremsstrahlung off a diamond. The crystal was oriented to provide polarised photons in the energy range E _γ = 800 to 1400MeV with the maximum polarisation of P _γ = 49 % obtained at 1305MeV. Both dominant decay modes of the η into two photons and 3π⁰ were used to extract the beam asymmetry from the azimuthal modulation of the cross-section. The measurements cover the angular range Θ_cm ≃ 50 -150 degrees. Large asymmetries up to 80% are observed, in agreement with a previous measurement. The eta-MAID model and the Bonn-Gatchina partial wave analysis describe the measurements, but the required partial waves differ significantly.     

On the possibility for precision measurements of differential cross sections for elastic proton–proton scattering at the Protvino accelerator

Elastic-scattering data were analyzed, and it was concluded on the basis of this analysis that precisionmeasurements of differential cross sections for elastic proton–proton scattering at the accelerator of the Institute for High Energy Physics (IHEP, Protvino, Russia) over a broad momentum-transfer range are of importance and topical interest. The layout of the respective experimental facility detecting the scattered particle and recoil proton and possessing a high momentum-transfer resolution was examined along with the equipment constituting this facility. The facility in question is able to record up to a billion events of elastic proton–proton scattering per IHEP accelerator run (20 days). Other lines of physics research with this facility are briefly discussed.     

Ionoluminescence and formation of color centers in α-Al2O3 single crystals under proton irradiation

This paper describes results of experimental studies on radiation defects in nominally pure single crystals of corundum in two initial states: α-Al₂O₃ with an unperturbed lattice and α-Al₂O₃:C with a high concentration of anion vacancies. Defects were identified from optical absorption spectra, ionoluminescence, pulsed cathodoluminescence and photoluminescence spectra. It is shown that mostly color centers of the F- and F⁺-types are formed in the α-Al₂O₃ lattice under irradiation with 5,7 MeV protons.     

Application of polarization methods to the detection of “latent” absorption bands of a food color

A spectral-optical investigation of the color of the red plum peel found in different aggregate states has been performed with the aim of its standardization in accordance with the demands of the food industry. The absorption spectra as well as the rotary dispersion and linear dichroism spectra of this food color have been obtained. The latter made it possible to reveal bands of individual pigments of the above-indicated color, “latent” in its absorption spectrum, and determine the positions of their maxima. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 563–565, July–August, 1999.     

Prompt photon production in proton–nucleus collisions at LHC: a comparison among color dipole models

The nuclear modification factor for prompt photon production in proton–nucleus collisions is investigated within color dipole formalism. By means of the Glauber–Gribov approach, the nuclear effects are studied in various rapidity bins with the evolution equation-based saturation models and the phenomenological dipole models. The theoretical results are compared with the experimental data provided by PHENIX, ATLAS and CMS Collaborations. At forward rapidity and midrapidity, a reasonable agreement...     

On “geometric” effects in the microwave radiation of active regions passing through the solar disk

Two basic “geometric” effects manifest themselves as slow variations in the properties of the microwave radiation of the active region passing through the solar disk, namely 1) sign inversions of the circular polarization and 2) characteristic peaks of the brightness temperature at certain longitudes on both sides of the central solar meridian and depression near it. These effects are related to the magnetic directivity of the cyclotron radiation governing in the centimeter wavelength range above large spots. The concept of “normal” passage of the active region through the solar disk is introduced in this paper on the basis of studying the mentioned effects observed at two wavelengths, 5.2 cm (Siberian Solar Radiotelescope, Buryatiya) and 1.76 cm (Radioheliograph in Nobeyama, Japan), to separate the “normal,” or “geometric” effects, in the behavior of the microwave radiation from the evolutional effects that may cause high-power solar flares. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 8, pp. 641–659, August 2008.     

Structure of the proton emitter La studied by proton and γ-ray spectroscopy

Proton radioactivity from ¹¹⁷La was re-investigated with much improved statistics and precision. Only the ground-state proton decay (Ep=813(3) keV, T1/2=20.1(25) ms) was observed, no evidence for a previously reported isomeric proton decay was found. Prompt γ rays in ¹¹⁷La were identified using the Recoil-Decay Tagging method. Overall the data indicate that the proton-emitting state is associated with a Kπ=3/²⁺ configuration, in agreement with all the published proton-decay calculations and predictions for the ground-state configuration of ¹¹⁷La calculated in the framework of either adiabatic or non-adiabatic particle models. However, this is not in agreement with the most recent state-of-the-art quasi-particle non-adiabatic model calculations which predict a Kπ=7/²⁻ configuration.     

Cross section for the Drell–Yan process in proton–proton collisions at the Large Hadron Collider (LHC)

The cross sections for the Drell–Yan process at the c.m. collision energy of \(\sqrt s \) = 13 TeV were calculated, and the results of these calculations are presented. The systematic errors associated with the uncertainties in the quark and gluon distributions and with the choice of scale for factorization and for the running QCD coupling constant are considered.     

Comment on “Quantum discord through the generalized entropy in bipartite quantum states”

In [X.-W. Hou, Z.-P. Huang, S. Chen, Eur. Phys. J. D 68, 87 (2014)], Hou et al. present, using Tsallis’ entropy, possible generalizations of the quantum discord measure, finding original results. As for the mutual informations and discord, we show here that these two types of quantifiers can take negative values. In the two qubits instance we further determine in which regions they are non-negative. Additionally, we study alternative generalizations on the basis of Rényi entropies.