Complex Bifurcation from Real Paths

A new bifurcation phenomenon, called complex bifurcation, is studied. The basic idea is simply that real solution paths of real analytic problems frequently have complex paths bifurcating from them. It is shown that this phenomenon occurs at fold points, at pitchfork bifurcation points, and at isola centers. It is also shown that perturbed bifurcations can yield two disjoint real solution branches that are connected by complex paths bifurcating from the perturbed solution paths. This may be useful in finding new real solutions. A discussion of how existing codes for computing real solution paths may be trivially modified to compute complex paths is included, and examples of numerically computed complex solution paths for a nonlinear two point boundary value problem, and a problem from fluid mechanics are given

High-voltage pulse generator developed for wide-gap spark chambers

Low-inductance, high-capacitance Marx pulse generator provides for minimization of internal inductance and suppression of external electromagnetic radiation. The spark gaps of the generator are enclosed in a pressurized nitrogen atmosphere which allows the charging voltage to be varied by changing the nitrogen pressure

W Plus Heavy Quark Production at the Tevatron

We summarize the motivations for and the status of the calculation of the $W +$ heavy quark production process in $p \bar p$ colliders to Next-to-Leading Order in QCD. This process can be used to constrain the strange quark distribution function at high $Q^2$ at the Tevatron, and also to study the bottom content of $W+1$~jet events. In addition, when crossed, the calculation essentially describes the single top quark production process to Next-to-Leading Order in QCD.Comment: Presented by S. Keller at DPF94 Meeting, Albuquerque, New Mexico, August 1-6,1994. 4 pages, no macros, no figures. Fermilab-Conf-94/260-T, FSU--HEP--940817. A postscript file is available via anonymous ftp at hepsg1.physics.fsu.edu, file is /pub/keller/fsu-hep-940817.p

Molecular orientation entanglement and temporal Bell-type inequalities

We detail and extend the results of [Milman {\it et al.}, Phys. Rev. Lett. {\bf 99}, 130405 (2007)] on Bell-type inequalities based on correlations between measurements of continuous observables performed on trapped molecular systems. We show that for some observables with a continuous spectrum which is bounded, one is able to construct non-locality tests sharing common properties with those for two-level systems. The specific observable studied here is molecular spatial orientation, and it can be experimentally measured for single molecules, as required in our protocol. We also provide some useful general properties of the derived inequalities and study their robustness to noise. Finally, we detail possible experimental scenarii and analyze the role played by different experimental parameters.Comment: 10 pages and 5 figure