Coulomb-hadron phase factor and spin phenomena in a wide region of transfer momenta

The Coulomb-hadron interference effects are examined at small and large $t$. The methods for the definition of spin-dependent parts of hadron scattering amplitude are presented. The additional contributions to analyzing power $A_N$ and the double spin correlation parameter $A_{NN}$ owing to the electromagnetic-hadron interference are determined in the diffraction dip domain of high-energy elastic hadron scattering.Comment: 9 pages, LaTeX, 4 figure

The Symplectic Penrose Kite

The purpose of this article is to view the Penrose kite from the perspective of symplectic geometry.Comment: 24 pages, 7 figures, minor changes in last version, to appear in Comm. Math. Phys

Magnetocaloric Studies of the Peak Effect in Nb

We report a magnetocaloric study of the peak effect and Bragg glass transition in a Nb single crystal. The thermomagnetic effects due to vortex flow into and out of the sample are measured. The magnetocaloric signature of the peak effect anomaly is identified. It is found that the peak effect disappears in magnetocaloric measurements at fields significantly higher than those reported in previous ac-susceptometry measurements. Investigation of the superconducting to normal transition reveals that the disappearance of the bulk peak effect is related to inhomogeneity broadening of the superconducting transition. The emerging picture also explains the concurrent disappearance of the peak effect and surface superconductivity, which was reported previously in the sample under investigation. Based on our findings we discuss the possibilities of multicriticality associated with the disappearance of the peak effect.Comment: 30 pages, 10 figure

Physical Structure of Planetary Nebulae. I. The Owl Nebula

The Owl Nebula is a triple-shell planetary nebula with the outermost shell being a faint bow-shaped halo. We have obtained deep narrow-band images and high-dispersion echelle spectra in the H-alpha, [O III], and [N II] emission lines to determine the physical structure of each shell in the nebula. These spatio-kinematic data allow us to rule out hydrodynamic models that can reproduce only the nebular morphology. Our analysis shows that the inner shell of the main nebula is slightly elongated with a bipolar cavity along its major axis, the outer nebula is a filled envelope co-expanding with the inner shell at 40 km/s, and the halo has been braked by the interstellar medium as the Owl Nebula moves through it. To explain the morphology and kinematics of the Owl Nebula, we suggest the following scenario for its formation and evolution. The early mass loss at the TP-AGB phase forms the halo, and the superwind at the end of the AGB phase forms the main nebula. The subsequent fast stellar wind compressed the superwind to form the inner shell and excavated an elongated cavity at the center, but has ceased in the past. At the current old age, the inner shell is backfilling the central cavity.Comment: 10 pages, 6 figures, 1 table, to appear in the Astronomical Journa

Using Molecules to Measure Nuclear Spin-Dependent Parity Violation

Nuclear spin-dependent parity violation arises from weak interactions between electrons and nucleons, and from nuclear anapole moments. We outline a method to measure such effects, using a Stark-interference technique to determine the mixing between opposite-parity rotational/hyperfine levels of ground-state molecules. The technique is applicable to nuclei over a wide range of atomic number, in diatomic species that are theoretically tractable for interpretation. This should provide data on anapole moments of many nuclei, and on previously unmeasured neutral weak couplings

Relativistic Effects in S-Wave Quarkonium Decay

The decay widths of S-wave quarkonia (\etc,\etb\to \gg{~~and~~} \J,\U\to\ee) are calculated on the basis of a quasipotential approach. The nontrivial dependence on relative quark motion of decay amplitude is taken into consideration via quarkonium wave function. It is shown that relativistic corrections may be large (10-50 %) and comparable with QCD corrections.Comment: 10 pages, no figure

Inventions of Scientists, Engineers and Specialists from Different Countries in the Area of Nanotechnologies. Part IV

Introduction. Advanced technologies impress people\u27s imagination demonstrating the latest achievements (materials, methods, systems, technologies, devices etc.) that dramatically change the world. This, first of all, concerns nanotechnological inventions designed by scientists, engineers and specialists from different countries. Main part. The paper briefly reviews inventions made by scientists, engineers and specialists from different countries: Russia, USA, China, Belarus, Great Britain, Vietnam, Denmark, the Kyrgyz Republic. The application of the results of scientists\u27, engineers\u27 and specialists\u27 investigations, including inventions in the area of nanotechnology and nanomaterials allow achieving significant efficiency in construction, house and communal service, related sectors of economy. For example, the invention A method to modify concrete with complex additive which includes hydrothermal nanoparticles SiO2 and multi-layer carbon nanotubes refers to methods of modifying concrete by introducing combination of nanoparticles with high specific surface into concrete mixture and can be used in production of precast and monolithic parts and structures of buildings and facilities of different purpose. This method of nanomodifying concrete makes it possible to achieve increased mechanical characteristics of concrete: compressive strength (25-77% at the age of 28 days) and bending strength, resistance to damage, Young\u27s mod of elasticity and shearing modulus, density (up to 10%), accelerated hardening at the early age and rate of strength development, decreased water absorbtion ability and improved indicators of porous structure (pore size and pore differential size uniformity), decreased total capillary porosity, increased frost resistance. The specialists can also be interested in the following nanotechnological inventions: a method to obtain polycrystalline diamond films; phase change materials for building construction: an overview of nano-/microencapsulation, solar collector of transpiration type; a method to obtain composition for antimicrobic coating on the basis of silver sulphide associates with molecules of methylene blue; broadband electromagnetic absorbing coating; a method to produce dry building mixtures; self-organizing nanostructures and separation membrane including aquaporin water channels and the methods to produce and use them; a method to obtain nanocrystalline titanium dioxide with anatase structure, etc. Conclusion. One of the most challenging tasks the economy of every country face is to increase industrial competitiveness through technological upgrade. From the side of the state and companies the principal object to control in this process are the people and enterprises dealing with introduction of inventions and new technologies

The Stark effect in linear potentials

We examine the Stark effect (the second-order shift in the energy spectrum due to an external constant force) for two 1-dimensional model quantum mechanical systems described by linear potentials, the so-called quantum bouncer (defined by V(z) = Fz for z>0 and V(z) infinite for z<0) and the symmetric linear potential (given by V(z) = F|z|). We show how straightforward use of the most obvious properties of the Airy function solutions and simple Taylor expansions give closed form results for the Stark shifts in both systems. These exact results are then compared to other approximation techniques, such as perturbation theory and WKB methods. These expressions add to the small number of closed-form descriptions available for the Stark effect in model quantum mechanical systems.Comment: 15 pages. To appear in Eur. J. Phys. Needs Institute of Physics (iopart) style file

Standard Model Higgs Physics at a 4 TeV Upgraded Tevatron

We compute an array of Standard Model Higgs boson (\hsm) signals and backgrounds for a possible upgrade of the Tevatron to E_{\rm cm}=4\tev. Taking \mt\geq 140\gev, and assuming a total accumulated luminosity of L=30\fbi, we find that a Standard Model Higgs boson with \mhsm\lsim 110\gev could almost certainly be detected using the \wpm\hsm\rta l\nu b\anti b mode. A Higgs boson with mass between \sim 120\gev and \sim 140\gev or above \sim 230-250\gev almost certainly would not be seen. A Higgs boson with \mhsm\sim 150\gev or 200\lsim\mhsm\lsim 230-250\gev has a decent chance of being detected in the ZZ\rta 4l mode. There would also be some possibility of discovering the \hsm in the WW\rta l\nu jj mode for 150\lsim\mhsm\lsim 200\gev. Finally, hints of an event excess in the WW\rta ll \nu\nu mode due to the \hsm might emerge for 140\lsim\mhsm\lsim 180\gev. Given the difficult nature of the Higgs boson signals for \mhsm values beyond the reach of LEP-200, and the discontinuous \mhsm range that could potentially be probed, justification of an upgrade of the Tevatron to 4\tev on the basis of its potential for Standard Model Higgs boson discovery would seem inappropriate.Comment: 21 pages; requires phyzzx.tex and tables.tex; full postscript file including embedded figures available via anonymous ftp at ucdhep.ucdavis.edu as [anonymous.gunion]4tev.ps, preprint UCD-94-1