OpenAccess

We demonstrate near-atomic-resolution Bragg diffraction from aerosolized single granulovirus crystals using an x-ray free-electron laser. The form of the aerosol injector is nearly identical to conventional liquid-microjet nozzles, but the x-ray-scattering background is reduced by several orders of magnitude by the use of helium carrier gas rather than liquid. [...]

In the framework of Feynman's quark--parton model for inclusive electroproduction and quark model of Ezawa, Maharana and Miyazawa for hadronic inclusive processes, relations between invariant cross sections for electroproduction of pions and purely hadronic production of pions in the beam fragmentation regions are derived. They are satisfied by data. [...]

We discuss the photon fragmentation region of inclusive pion photo- and electroproduction in terms of a helicity dependent Mueller-Regge model, in which cut contributions are taken into accout. It is shown that the inadequacies of a pure Regge pole expansion can be corrected if certain types of Regge cut contributions are included. [...]

We develop a method for investigating the asymptotic behaviour of vertex functions at certain Minkowskian exceptional momenta. It is a direct generalization of earlier treatments of Euclidean exceptional momenta. [...]

A covariant perturbation scheme is developed to give a coordinate independent perturbation expansion of the chiral invariant pion model with nucleons. On the mass shell the covariant approach is shown to be equivalent to the standard perturbation theory..

The design and characterization of a new laser-desorption molecular beam source, tailored for use in x-ray free-electron laser and ultrashort-pulse laser imaging experiments, is presented. It consists of a single mechanical unit containing all source components, including the molecular-beam valve, the sample, and the fiber-coupled desorption laser, which is movable in five axes, as required for experiments at central facilities. [...]