1. Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Madrid, Spain
2. Wigner Fizikai Kutatokozpont, Budapest, Hungary
3. Paul Scherrer Institut, Villigen, Switzerland
4. Laboratory of Accelerators and Applied Superconductivity, National Institute for Nuclear Physics, Milan Section, Milano, Italy
5. CERN, Geneva, Switzerland
6. Commissariat a l'energie Atomique et Aux Energies Alternatives, Saclay, France