1. Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova St., Nizhny Novgorod, Russia
2. Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina St., Nizhny Novgorod, Russia
3. Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region, Russia
4. Department of Physics, University of Jyväskylä, Jyväskylä, Finland