Affiliation: | (1) Research Institute of Physics (Petrodvorets Branch), St. Petersburg State University, Peterhof, 198504, Russia;(2) Institute of Atomic Physics and Spectroscopy, University of Latvia, LV-1586 Riga, Latvia;(3) National Institute for Nuclear Physics, Fermi Department of Physics, University of Pisa, I-56127 Pisa, Italy |