Parity-odd asymmetries in W-jet events at the fermilab tevatron

Parity-odd asymmetries in the decay angular distribution of a W boson produced with a hard jet in pp[over ] collisions arise only from QCD rescattering effects. If observed, these asymmetries will provide a first demonstration that perturbative QCD calculation is valid for the absorptive part of scattering amplitudes. We propose a simple observable to measure these asymmetries and perform realistic Monte Carlo simulations at energies reached at the Fermilab Tevatron. It is shown that the Tevatron run II should provide sufficient statistics to test the prediction.     

Bulk electronic structure of the antiferromagnetic superconducting phase in ErNi2B2C

We have performed temperature- (T-)dependent laser-photoemission spectroscopy of the antiferromagnetic (AF) superconductor ErNi2B2C to study the electronic-structure evolution reflecting the interplay between antiferromagnetism and superconductivity. The spectra at the superconducting (SC) phase show a very broad spectral shape. A T-dependent SC gap shows a sudden deviation from the BCS prediction just below TN. This observation can be explained well by the theoretical model and thus represents the characteristic bulk electronic structure of the AF SC phase for the first time.     

Near EF electronic structure of heavily boron-doped superconducting diamond

We have performed soft X-ray angle-resolved photoemission spectroscopy (SXARPES) of a heavily boron-doped superconducting diamond film (T_c=7.2 K) in order to study the electronic structure near the Fermi level (E_F). Careful determination of measured momentum space that across Γ point in the Brillouin zone (BZ) and increase of an energy resolution provide further spectroscopic evidence that E_F is located at the highly dispersive diamond-like bands, indicating that holes at the top of the diamond-like valence band play an essential role for the conducting properties of the heavily boron-doped superconducting diamond for this boron-doping region (effective carrier concentration of 1.6%). The SXARPES intensities at E_F were also mapped out over BZ to obtain experimental Fermi surface sheets and compared with calculations.     

Temperature-dependent localized excitations of doped carriers in superconducting diamond

Laser-excited photoemission spectroscopy is used to show that the doped carriers in metallic or superconducting diamond couple strongly to the lattice via high-energy (approximately 150 meV) optical phonons, with direct observations of localized Franck-Condon multiphonon sidebands appearing as Fermi-edge replicas. It exhibits a temperature-dependent spectral weight transfer from higher to lower energy sidebands and zero-phonon Fermi-edge states. The quantified coupling strength shows a systematic increase on lowering temperature, implicating its relation to the normal state transport and superconductivity.     

Critical heat flux of liquid helium (I) in forced convective boiling

For liquid helium (I) flowing through a uniformly heated vertical tube of 1 mm i.d., critical heat flux (CHF) of forced convective boiling has been measured under the conditions of a pressure of 0.199 MPa with vapor-to-liquid density ratio, of 0.409, length-to-diameter ratios from 25 to 200, mass velocities from 11 to 108 kg m^?2 s^?1, and inlet subcooling enthalpy from ?3.5 to +7.0 kJ kg^?1. The experimental results thus obtained are analyzed revealing that the high pressure character, which has already been observed for water and Freons at extremely high pressures, is certainly found at high mass velocities for liquid helium too, though its appearance is restricted within very narrow limits due to the phenomenon that the wall temperature situation identifying the CHF condition fades away when the mass velocity becomes high.     

CeO<Subscript>2</Subscript> nanoparticle-modified electrode as a novel electrochemical interface in the quantification of Zn<Superscript>2+ </Superscript>ions at trace level: application to real sample analysis

A simple strategy has been proposed to quantify Zn²⁺ ions using CeO₂ nanoparticle-modified glassy carbon electrode. The CeO₂ nanoparticles were prepared by sucrose-nitrate decomposition method, and it was characterized by X-ray diffraction (XRD), FT-IR, TEM, and surface area analyzer. The synthesized CeO₂ nanoparticles were used as modifier molecules as a thin film on glassy carbon electrode (GCE) in the trace level quantification of Zn²⁺ by using cyclic voltammetry (CV) and differential pulse anodic stripping voltammetry (DPASV) techniques. The fabricated sensor exhibited a good analytical response towards Zn²⁺ ions. The modified electrode showed a wide linearity in the concentration range 20–380 μg L^?1 with a limit of detection 0.36 μg L^?1. The proposed electrochemical sensor was successfully applied to trace level Zn²⁺ quantification from real sample matrices.     

Preparation of renieramycin left-half model compounds

Model compounds of the left-half of renieramycins, which are anticancer marine natural products having an α-aminonitrile functionality, were prepared from phenylalanine derivatives. The key step of the transformation is the stereospecific construction of 1,3-cis stereochemistry via an exomethylene intermediate. The stereoselective α-aminonitrile formation under kinetically controlled conditions is also discussed. The initial cytotoxicity profiles are presented.