Hadronic photon interactions at high energies

A simple phenomenological introduction to the physics of multi-pomeron exchange amplitudes in connection with the Abramovski-Gribov-Kancheli (AGK) cutting rules is given. The AGK cutting rules are applied to obtain qualitative and quantitative predictions on multiparticle production at high energies. On this basis, particle production in hadron-hadron scattering, photoproduction, and in particular the transition to deep-inelastic scattering is discussed.Comment: LaTeX, 6 pages, 6 ps-figs, sprocl.sty, talk given by R. Engel at "XXVI International Symposium on Multiparticle Dynamics" held in Faro, Portugal, September 199

Quantum oscillations observed in graphene at microwave frequencies

We have measured the microwave conductance of mechanically exfoliated graphene at frequencies up to 8.5 GHz. The conductance at 4.2 K exhibits quantum oscillations, and is independent of the frequency

Superconductivity-Related Insulating Behavior

We present the results of an experimental study of superconducting, disordered, thin-films of amorphous Indium Oxide. These films can be driven from the superconducting phase to a reentrant insulating state by the application of a perpendicular magnetic field ($B$). We find that the high-$B$ insulator exhibits activated transport with a characteristic temperature, $T_I$. $T_I$ has a maximum value ($T_{I}^p$) that is close to the superconducting transition temperature ($T_c$) at $B$ = 0, suggesting a possible relation between the conduction mechanisms in the superconducting and insulating phases. $T_{I}^p$ and $T_c$ display opposite dependences on the disorder strength.Comment: Tex file and 5 figures; Revised version; To appear in Phys. Rev. Lett. (2004

Mesoscopic Spin-Hall Effect in 2D electron systems with smooth boundaries

Spin-Hall effect in ballistic 2D electron gas with Rashba-type spin-orbit coupling and smooth edge confinement is studied. We predict that the interplay of semiclassical electron motion and quantum dynamics of spins leads to several distinct features in spin density along the edge that originate from accumulation of turning points from many classical trajectories. Strong peak is found near a point of the vanishing of electron Fermi velocity in the lower spin-split subband. It is followed by a strip of negative spin density that extends until the crossing of the local Fermi energy with the degeneracy point where the two spin subbands intersect. Beyond this crossing there is a wide region of a smooth positive spin density. The total amount of spin accumulated in each of these features exceeds greatly the net spin across the entire edge. The features become more pronounced for shallower boundary potentials, controlled by gating in typical experimental setups.Comment: 4 pages, 4 figures, published versio

Special Economic Zones, Global Value Chains, and the Degree of Economic Linkages in the Dominican Republic

The Dominican Republic is often considered an example of the successful implementation of Special Economic Zones (henceforth SEZs) in the Western hemisphere. The zones fueled economic growth during the 1980s and 1990s and, while they experienced a sharp decline in employment due in part to the expiry of the end of the Multi-Fiber Agreement and stronger international competition in the textile and apparel industry in 2005, signs of recovery have been observed since 2009. Surgical equipment, chemicals and plastics, and footwear have recently emerged as the new drivers of export dynamism in the zones (World Bank, 2015). The objective of this report is to inform the policy discussion around the developmental impact of SEZs in the Dominican Republic by empirically assessing i) the implications of regulatory reforms aimed at complying with WTO disciplines regarding the elimination of incentives conditioned on export performance for SEZs firms, ii) the extent to which SEZs participate in Global Value Chains, and iii) their linkages with domestic suppliers. The report is organized as follows: The second section presents the historical importance of SEZ as an engine of economic growth in the country. The third section depicts the structural shift in terms of production in SEZs and evaluates the degree of value addition taking place in the Dominican Republic. The fourth section evaluates the degree and evolution of linkages between SEZs and local firms. The fifth section shows the impact of the regulatory changes in the SEZ regimen undertaken to comply with WTO disciplines. Finally, some conclusions and policy recommendations are presented in section six

Test and analysis of design of a manifold and reentrant tube assembly. Task 3A - Feasibility of a chemical poison loop system Summary report

Poison control tube and manifold system for reactivity control of tungsten water moderated rocket reacto

Spin magnetotransport in two-dimensional hole systems

Spin current of two-dimensional holes occupying the ground-state subband in an asymmetric quantum well and interacting with static disorder potential is calculated in the presence of a weak magnetic field H perpendicular to the well plane. Both spin-orbit coupling and Zeeman coupling are taken into account. It is shown that the applied electric field excites both the transverse (spin-Hall) and diagonal spin currents, the latter changes its sign at a finite H and becomes greater than the spin-Hall current as H increases. The effective spin-Hall conductivity introduced to describe the spin response in Hall bars is considerably enhanced by the magnetic field in the case of weak disorder and demonstrates a non-monotonic dependence on H.Comment: 4 pages, 2 figures, published in Phys. Rev.

Equilibrium spin currents: Non-Abelian gauge invariance and color diamagnetism in condensed matter

The spin-orbit (SO) interaction in condensed matter can be described in terms of a non-Abelian potential known in high-energy physics as a color field. I show that a magnetic component of this color field inevitably generates diamagnetic color currents which are just the equilibrium spin currents discussed in a condensed matter context. These dissipationless spin currents thus represent a universal property of systems with SO interaction. In semiconductors with linear SO coupling the spin currents are related to the effective non-Abelian field via Yang-Mills magnetostatics equation.Comment: RevTeX, 4 page