[en] Several methods have been devised to measure the weak phase γ using decays of the type B^± -> DΚ^± where it is assumed that there is no mixing in the D⁰--anti-D⁰ system. However, when using these methods to uncover new physics, one must entertain the real possibility that the measurements are affected by new physics effects in the D₀--anti-D⁰ system. The authors show that even values of x_D/or y_D around 10^-2 can have a significant impact in the measurement of sin² γ. The authors discuss the errors incurred in neglecting this effect, how the effect can be checked, and how to include it in the analysis

[en] The feasibility of ion separation through adsorption on carbon electrodes was investigated by electroadsorption of the following ions: Li⁺, Na⁺, Sr²⁺ and Mg²⁺. No meaningful differences were observed in the adsorption of these ions on two types of carbon powder electrodes. Therfore, these electrodes cannot be used for isotope separation. Examination of ultramicroporus carbon electrodes as well as TiS₂ electrodes is suggested

[en] Published in summary form only

[en] The modified free Hamiltonian for the Coulomb interaction is used to derive an equation for the S-matrix and renormalized asymptotic states. We obtain an effective potential and the corresponding finite perturbation expansion for the S-matrix. The Born approximation is shown to contain a term (α/vertical strokepvertical stroke)delta₃(p-p') the (divergent) phase correction which makes the second-order term finite is also explicitly derived. (orig.)

[en] A combination of geometric and algebraic methods is used to prove asymptotic completeness for Schroedinger-type equations with potential not vanishing at infinity along hyperboloids (in spacetime), and with the free Hamiltonian given by the (not bounded below) relativistic (mass)² operator. The proof is based on the use of a modified form of local compactness and additional geometric properties of asymptotic scattering states which are needed to distinguish them from states 'trapped' inside some hyperboloid for all times. (orig.)

[en] Electrochemical parametric pumping is a novel separation process in which cycles of reversible electrochemical processes on high surface area electrodes are conducted in synchronization with cycles of solution flow through the separating column. In the present work, isotope separation by electrochemical parametric pumping is studied theoretically. The proposed model is based on the similarity between the parametric pumping and the countercurrent processes and on the division of the separating column to cells when dispersion processes are neglected. Steady-state isotopic concentration gradients are calculated and process optimization is performed with respect to system parameters such as the fraction of the isotopes bound to the electrode, the solution displacement volume, and the fraction of the isotopes withdrawn as product. The model may also be applicable to other types of parametric pumping. 20 references, 13 figures

[en] Several methods have been devised for measuring the weak phase γ using decays of the type B→DK. It is shown that these and other direct CP-violation measurements suffer from discrete ambiguity which is at least 8-fold. Combining two measurement methods helps reduce the ambiguity and the experimental error. The measurement sensitivity and new physics discovery potential are estimated using a full Monte Carlo detector simulation with realistic background estimates, giving particular consideration to ambiguities. copyright 1999 The American Physical Society

[en] Published in summary form only

[en] The pore structure of a fibrous carbon molecular sieve has been studied by adsorption of CO₂,O₂,C₂H₂,N₂,CO,Xe,Ar and SF₆ as molecular probes. Apart from the negligible outer surface of the fibres, all adsorption sites possess molecular sieving properties. Mild activation steps enable the graduated opening of critical pore dimensions in the range 3.1 to 5.6 A, which keeps adsorption selectivity between molecules varying by merely 0.2 A in cross-section >>100:1. The pore opening is effected by removing surface groups as CO₂ and CO due to degassing at temperatures from 100 to 700⁰C and by burning off skeletal carbon atoms in air at 400 to 450⁰C. Degassing at temperatures >800⁰C leads to pore closure due to sintering. Removal of surface atoms must result in pore widening by steps as large as a few Angstroms, in contradistinction to the observed graduated pore opening. It is anticipated, therefore, that the fine discrimination between molecules of similar dimensions is of kinetic-statistical origin, so that molecular sieving by pores, substantially greater than the molecules considered, is possible. The detailed model is based on the existence of a few rate-determining constrictions close to the outer surface of the fibres and of wider pores composing the major part of the pore volume. (author)

[en] Published in summary form only