Precise measurement of the CP violation parameter sin2φ1 in B0→(cc¯)K0 decays

We present a precise measurement of the CP violation parameter sin2φ1 and the direct CP violation parameter A(f) using the final data sample of 772×10(6) BB[over ˉ] pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is reconstructed in a J/ψK(S)(0), ψ(2S)K(S)(0), χ(c1)K(S)(0), or J/ψK(L)(0) CP eigenstate and its flavor is identified from the decay products of the accompanying B meson. From the distribution of proper-time intervals between the two B decays, we obtain the following CP violation parameters: sin2φ1=0.667±0.023(stat)±0.012(syst) and A(f)=0.006±0.016(stat)±0.012(syst).     

Photoluminescence and electric spectroscopy of dislocation-induced electronic levels in semi-insulated CdTe and CdZnTe

We studied deformation-induced defects in semi-insulating CdTe and CdZnTe by infrared photoluminescence (PL), contact less photoconductivity and resistivity. Plastic deformation increased the concentrations of grown-in defects, namely, those of an important midgap level E_C−0.74 eV in CdTe and Cd_1−xZn_xTe (x<0.1), the materials of choice in today’s X-ray and gamma ray detector technology. We confirmed the direct correlation between Y-emission and the dislocation density in both compounds. The Y-band intensified near an indenter deformation or near a scribing line, but was barely visible in low-dislocation areas (etch pit density <2×10⁵ cm⁻²). Our results correlate with recent findings that dislocation-induced defects and their clusters degrade charge collection in radiation detectors. Photoluminescence of midgap levels can serve as a tool to identify areas of degraded performance in semi insulated CdTe and CdZnTe crystals for radiation detectors.     

Tunable THz metamaterials based on an array of paraelectric SrTiO<Subscript>3</Subscript> rods

This work presents theoretical and experimental investigations of a tunable metamaterial which exhibits negative permeability in the THz frequency range. The tunability is obtained by temperature changes, and the sample consists of an array of high-permittivity SrTiO₃ (STO) rods micromachined by a femtosecond laser. Structures exhibiting a negative permeability on multiple frequency bands are also investigated and a proper choice of the dimensions of the pattern allows us to achieve a substantial broadening of the frequency band with negative μ.     

Eliashberg theory for disordered superconductors. II. Tunneling into disordered two-dimensional Pb films

A series ofc-axis oriented YBa₂Cu₃O _x -films with different oxygen content were prepared by laser deposition. The oxygen contentx was determined by X-ray diffraction and by resonant Rutherford-back-scattering (RRBS) measurements. Thec-axis length in these films of YBa₂Cu₃O _x is about 0.5% larger compared to bulk values. We describe transport measurements in magnetic fields up to 7 Tesla between room temperature andT _c in samples with an oxygen content between the orthorhombic-to-tetragonal transition (x6.4) and full oxygenation (x7). The ratio /R _H was investigated with respect to the two-dimensional Luttinger liquid theory and the model of the two-dimensional ionic metal. We report on deviations from the expected quadratic temperature behaviour of /R _H , especially in films with high oxygen content.     

56,57,60CoFe NMR/ON,hyperfine anomalies and γ-factors of cobalt isotopes

The results of NMR/ON measurements on^56'57'60Co isotopes in iron are presented. To avoid the uncertainties caused by local demagnetizing field inhomogenities the measurements on two cobalt isotopes in one sample have been carried out. The values of nuclear-factor ratios ⁵⁷/ ⁶⁰ = 1.805 (20), ⁶⁰/ ⁵⁶ = 0.761 (20), ⁵⁶/ ⁵⁷ = 0.726 (20) and hyperfine anomalies⁵⁶⁶⁰ = -0.036 (10),^{60 57} = 0.017 (10) and⁵⁷⁵⁶ = 0.018 (10) have been calculated from the experimental results.     

Intermetallic compounds as negative electrodes of Ni/MH batteries

This review is devoted to the main families of thermodynamically stable intermetallic compounds (AB₅-, AB₂- and AB-type alloys) that have been researched in the last thirty years as materials for negative electrodes in nickel–metal hydride batteries. The crystal structure of these compounds and their hydrides is widely described. Their solid–gas hydrogenation properties and, particularly, the related desorption isotherm curves are examined as a useful criterion for the selection of suitable battery materials. The electrochemical performances obtained with these alloys are reported and the given solutions to common problems such as corrosion, passivation, decrepitation and short cycle life are discussed. Only AB₅-based compounds have achieved, up to now, enough development for being widely present on the market, and exhibit improved battery performances in comparison with the polluting Ni/Cd batteries. The high capacity of AB₂-based compounds and the remarkable electrochemical activity of some AB-based alloys make, however, further research on all the reviewed families still valuable. Received: 16 August 2000 / Accepted: 6 November 2000 / Published online: 9 February 2001     

Indirect optical crosstalk reduction by highly-doped backside layer in single-photon avalanche diode arrays

A method of reducing indirect optical crosstalk in single-photon avalanche diode arrays is investigated by TCAD simulations. The reduction is accomplished by taking advantage of an enhanced optical absorption in a highly-doped Si layer on the backside of the wafer. A simulation environment was developed to give information about optical crosstalk by incorporating the experimental optical constants of the materials constituting the crosstalk-reduction layer. It is shown that the indirect optical crosstalk is greatly reduced by increasing the thickness and doping of the layer. A crosstalk reduction of 5 orders of magnitude is gained with addition of 1-μm-thick \(\hbox {PureB}/\upalpha \hbox {-Si}\) stack for the array processed on a p-type substrate, while the same reduction is achieved with a 1-μm-thick highly-doped Si layer (As, \(1.1\times 10^{20}\, \hbox {cm}^{-3}\)) for an array processed on an n-type substrate.     

Entangling atoms in photonic crystals

We propose a method for entangling a system of two-level atoms in photonic crystals. The atoms are assumed to move in void regions of a photonic crystal. The interaction between the atoms is mediated either via a defect mode or via a resonant dipole-dipole interaction. We show that these interactions can produce pure entangled atomic states. We analyze the problem with parameters typical for currently existing photonic crystals and Rydberg atoms and we show that the atoms can emerge from photonic crystals in entangled states. Depending on the linear dimensions of the crystal we estimate that a pair of atoms entangled in a photonic crystal can be separated by tens of centimeters. Receive 11 June 1999 and Received in final form 4 October 1999     

Distribution of stable isotopes in surface water along the Danube River in Serbia†

Stable hydrogen and oxygen isotopes were analysed in water samples from the River Danube and its tributaries during a longitudinal survey performed in August 2005 on Serbian territory. Danube river water data ranged from?80‰ to?66‰ for δ²H, and from?11.2‰ to?9.3‰ for δ¹⁸O with δ values increasing downstream. The isotopic signatures of the adjacent tributaries (the Tisza, the Sava and the Velika Morava) sampled at the locations close to their confluence with the Danube (Titel, Ostru?nica and Ljubi?evski most, respectively) just about the time of the campaign were enriched (?67‰ and?63‰ for δ²H, and?9.3‰ and?8.9‰ for δ¹⁸O) with respect to the Danube water because of their catchment effects. Hydrogen and oxygen stable isotope values were used in combination with measured physico-chemical and biological parameters to trace hydrological and transport processes in these river systems. The mixing relationships between the Danube main stream and its tributaries were estimated using the mass balance for isotopic composition and electrical conductivity as conservative parameters. Evidence of an incomplete mixing process at the ?enta location, 8 km below the confluence of the Tisza river, with its participation of 88% was shown by its oxygen-18 content. The correlations between river water isotope composition and physico-chemical and biological parameters are discussed.     

The Gelfand-Levitan equation and its application to the scattering of neutrons on protons

The Gelfand-Levitan equation for the kernelP(r, r) (withrr) is formulated and then applied for determining the scattering potential in the scattering of slow neutrons on protons (for the case when the dependence of the nuclear forces on the spins can be neglected and onlys-scattering need be considered). The potentials obtained are the same as the Bargmann ones, found by a different method.

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- P(r, r) ( rr). , ( s- ). , .