1. Institute
of Theoretical Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
2. Interdisciplinary
Centre for Mathematical and Computational Modelling, University of Warsaw, Prosta 69, 00-838 Warsaw, Poland
3. Hopkinson
Laboratory, Engineering Department, University of Cambridge, Trumpington
Street, Cambridge CB2 1PZ, UK