Documents in process

Abstract: A nitrogen-rich compound, ReN8·xN2, was synthesizedby a direct reaction between rhenium and nitrogen at highpressure and high temperature in a laser-heated diamond anvilcell. Single-crystal X-ray diffraction revealed that the crystalstructure, which is based on the ReN8 framework, hasrectangular-shaped channels that accommodate nitrogen molecules.Thus, despite a very high synthesis pressure, exceeding100 GPa, ReN8·xN2 is an inclusion compound. [...]

We consider the derivatives of Horn hypergeometric functions of any number variables with respect to their parameters. The derivative of the function in $n$ variables is expressed as a Horn hypergeometric series of $n+1$ infinite summations depending on the same variables and with the same region of convergence as for original Horn function. [...]

We have computed the contributions of the quartic Casimir invariants to the four-loop anomalous dimensions of twist-2 spin-N operators at N =< 16. The results provide new information on the structure of the next-to-next-to-next-to-leading order (N^3LO) splitting functions P_{ik}^(3)(x) for the evolution of parton distributions, and facilitate approximate expressions which include the quartic-Casimir contributions to the (light-like) gluon cusp anomalous dimension. [...]

In laser illuminated dielectric accelerators (DLA) high acceleration gradients can be achieved, due to high damage thresholds of the materials at optical frequencies. This is a necessity in developing more compact particle accelerator technologies. [...]

Over the past decade the production of multi-GeV electron beams from laser-driven plasma accelerators has been successfully demonstrated. However, demanding applications such as compact electron-driven X-ray sources require further improvements on beam energy spread and transverse emittance. [...]