The ratio of double-to-single ionization of He has been measured between 280 eV and 1210 eV to investigate its energy dependence in the intermediate region. The new intermediate energy measurement, compared with the most recent theories of Pan and Kelly and of Hino and Hino et al., show the importance of including not only ground state but also final state correlations. They also appear to indi...

In a recent paper [J. Math. Phys. 47 082303 (2006)], Quantum Energy Inequalities were used to place simple geometrical bounds on the energy densities of quantum fields in Minkowskian spacetime regions. Here, we refine this analysis for massive fields, obtaining more stringent bounds which decay exponentially in the mass. At the technical level this involves the determination of the asymptotic b...

There is no theoretical reason to think that the spin-flip component of the Pomeron is zero. One can measure the spin-flip part using Coulomb-nuclear interference (CNI). Perturbative QCD calculations show that the spin-flip component is sensitive to the smallest quark separation in the proton, while the non-flip part probes the largest separation. According to HERA results on the proton structu...

The sustainable development and energy security are currently the priority challenges for the European Union countries. The sustainable and stable development of European economies is closely dependent on the stable access to energy resources. The constant increase of the demand for electricity requires long-term planning of the common European policy. The aim of the article is to analyse the f...

Pion double charge exchange ~DCX! on nuclear targets has been extensively studied, both experimentally and theoretically, throughout the last two decades. Because at least two nucleons must be involved in the process, the study of DCX is a natural tool for exploring nucleon-nucleon correlations. In the course of these studies at low energies, a prominent peak in the (p,p) cross section in the n...

Using the data from the Rossi X-ray Timing Explorer (RXTE), we report the diierent energy dependence of the variability of the four persistent hard X-ray sources in the low-hard state: Cygnus X{1, GX 339{4, GRS 1758-258 and 1E 1740.7{2942. Cygnus X{1 is found to have a atter power density spectrum (PDS) shape at higher energies. The other three sources have energy independent PDS shapes. The en...