J-PARC E27 Experiment to Search for a Nuclear Kaon Bound State K − pp

In the J-PARC E27 experiment, we search for a K ^? pp bound state via the d(π ⁺, K ⁺) reaction at 1.7 GeV/c at the K1.8 beam line. The binding energy and decay width of the K ^? pp bound state can be obtained in the missing mass measurement with a good energy resolution of 2 MeV/c ². A range counter array (RCA) was constructed to detect the two high-momentum protons from the K ^? pp decay and to reduce the background such as quasi-free hyperon production. Recently, we have carried out a pilot run in June, 2012. The d(π ⁺, K ⁺) missing-mass spectrum has been obtained for the first time. In this report, an overview of the E27 experiment and a preliminary result on this pilot run are presented.     

Mutually beneficial relationship in optimization between search-space smoothing and stochastic search

The effectiveness of the Metropolis algorithm (MA) (constant-temperature simulated annealing) in optimization by the method of search-space smoothing (SSS) (potential smoothing) is studied on two types of random traveling salesman problems. The optimization mechanism of this hybrid approach (MASSS) is investigated by analyzing the exploration dynamics observed in the rugged landscape of the cost function (energy surface). The results show that the MA can be successfully utilized as a local search algorithm in the SSS approach. It is also clarified that the optimization characteristics of these two constituent methods are improved in a mutually beneficial manner in the MASSS run. Specifically, the relaxation dynamics generated by employing the MA work effectively even in a smoothed landscape and more advantage is taken of the guiding function proposed in the idea of SSS; this mechanism operates in an adaptive manner in the de-smoothing process and therefore the MASSS method maintains its optimization function over a wider temperature range than the MA.     

Theory of interacting donor electrons in the Anderson-localized regime of semiconductors

The current status of investigations for the rival effect of disorder and electron-electron interaction in the intermediate-concentration regime of doped semiconductors is reviewed from the standpoint of transfer-diagonal formulation. In particular, effects of electron-electron interaction on the electronic specific heat and magnetic properties at low temperatures are clarified, and theoretical results are compared with the experimental ones on phosphorusdoped silicon. The formulation to stimulate the Anderson-localized states in the intermediate concentration regime of doped semiconductors by a cluster model is presented, and the results of the computer simulation are discussed in detail.     

Variations of lattice constants and thermal expansion coefficients of indium at high pressure and high temperature

ABSTRACT

The effects of pressure and temperature on the lattice constants and thermal expansion coefficients of Indium were studied up to 18.6?GPa and 506?K based on in situ X-ray diffraction method with an externally heated diamond anvil cell. The results show that the measured axial ratio (c/a) decreases with increasing temperature and its temperature dependence decreases with increasing pressure. The thermal expansion coefficient of the a-axis decreases with increasing pressure up to 7?GPa and remains almost constant above 7?GPa, whereas that of the c-axis increases monotonously with pressure and changes from negative to positive at around 7?GPa. The observed behavior suggests that temperature reduces the tetragonal distortion on the lattice, and its effect is dominant below 7?GPa; in contrast, pressure enhances lattice distortion, and tends to have a stronger effect above 7?GPa.     

Nonlinear sharpening of holographically processed sub-microstructures

Wavelength dispersion of a computer-generated hologram causes spatial broadening of the focal spot in holographic femtosecond laser processing. From the paraxial approximation, we theoretically derived that the spatial broadening is proportional to only the diffraction position, defined as the distance from the optical axis. We performed experiments under the large-dispersion condition to analyze the influence of the diffraction position on the processed structure. In the processing experiment, a high-numerical-aperture lens and a laser energy near the threshold energy were used to fabricate sub-microstructures. We found a nonlinear dependence of the broadening of the processed structures on the diffraction position, and the degree of broadening was much smaller than the predicted value because of the nonlinear properties of the laser processing.     

Some remarks on superspecial and ordinary curves of low genus

In the first half of this paper, we investigate a superspecialty criterion with respect to $\lambda$ for the curve which is a generalization of a theorem for an elliptic curve by Max Deuring (1941). In the last half, we study a criterion with respect to the characteristic $p>0$ of the ground field such that the Picard curve is superspecial or ordinary. In the final section (appendix), we consider another viewpoint of the first result by using a fact that the first curve has a completely decomposable Jacobian.     

Oxidation of ultra-thin Ti films on Mo(100): Soft X-ray photoelectron spectroscopy study

Titanium oxide films grown on Mo(100) have been investigated by low-energy electron diffraction (LEED) and soft X-ray photoelectron spectroscopy (PES). The film was grown by Ti deposition on Mo(100) and subsequent oxidation of the film by 12 L of O₂ exposure at room temperature. As the film was annealed at 700–1000 °C, the film in which the Ti atoms were in a Ti³⁺ oxidation state was formed. As the film was annealed at 1100–1500 °C, the oxidation state of Ti in the film was converted to Ti²⁺. The valence electronic structure of the film was measured under the condition that the emission from the Mo substrate was minimized due to a Cooper minimum of the Mo 4 d photoionization cross sections (hν = 100 eV). It was found that the Ti 3 d band in normal-emission spectra was increased in intensity when the film was annealed at 1100–1500 °C. As the film was annealed at 1300 °C for 10 s and 20 s, the film-covered Mo(100) gave (2 × 2) and (4 × 1) LEED patterns, respectively. The two-dimensional band structure of the (2 × 2) system was investigated by angle-resolved PES, and it was found that the film with a (1 × 1) periodicity with respect to the Mo(100) substrate existed in the (2 × 2) system.     

Molecularly imprinted solid-phase extraction for the selective determination of methamphetamine, amphetamine, and methylenedioxyphenylalkylamine designer drugs in human whole blood by gas chromatography-mass spectrometry

A novel method is described for the extraction of methamphetamine, amphetamine, and methylenedioxyphenylalkylamine designer drugs, such as 3,4-methylenedioxy-methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxyethylamphetamine, N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine, and 3,4-(methylenedioxyphenyl)-2-butanamine, from human whole blood using molecularly imprinted solid-phase extraction as highly selective sample clean-up technique. Whole blood samples were diluted with 10 mmol/L ammonium acetate (pH 8.6) and applied to a SupelMIP-Amphetamine molecularly imprinted solid-phase extraction cartridge. The cartridge was then washed to eliminate interferences, and the amphetamines of interest were eluted with formic acid/methanol (1:100, v/v). After derivatization with trifluoroacetic anhydride, the analytes were quantified using gas chromatography-mass spectrometry. Recoveries of the seven amphetamines spiked into whole blood were 89.1-102%. The limits of quantification for each compound in 200 μL of whole blood were between 0.25 and 1.0 ng. The maximum intra- and inter-day coefficients of variation were 9.96 and 13.8%, respectively. The results show that methamphetamine, amphetamine, and methylenedioxyphenylalkyl-amine designer drugs can be efficiently extracted from crude biological samples such as whole blood by molecularly imprinted solid-phase extraction with good reproducibility. This extraction method will be useful for the pretreatment of human samples before gas chromatography-mass spectrometry.     

Entanglement Between Degrees of Freedom in?a?Single-Particle System Revealed in Neutron Interferometry

Initially Einstein, Podolsky, and Rosen (EPR) and later Bell shed light on the non-local properties exhibited by subsystems in quantum mechanics. Separately, Kochen and Specker analyzed sets of measurements of compatible observables and found that a consistent coexistence of these results is impossible, i.e., quantum indefiniteness of measurement results. As a consequence, quantum contextuality, a more general concept compared to non-locality, leads to striking phenomena predicted by quantum theory. Here, we report neutron interferometric experiments which investigate entangled states in a single-particle system: entanglement is, in this case, achieved not between particles, but between degrees of freedom i.e., between spin, path, and energy degrees of freedom. Appropriate combinations of the spin analysis and the position of the phase shifter in the interferometer allow an experimental verification of the violation of a Bell-like inequality. In addition, state tomography, tomographic analysis of the density matrix of a quantum system, and Kochen-Specker-like phenomena are presented to characterize neutrons’ entangled states and their peculiarity. Furthermore, a coherent energy manipulation scheme is accomplished with a radio-frequency (RF) spin-flipper. This scheme allows the (total) energy degree of freedom to be entangled: the remarkable behavior of a triply entangled GHZ-like state is demonstrated.