1. SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
2. Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
3. Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305, USA
4. Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg, Germany