[1] Herzen State Pedag Univ Russia, Phys Dept, St Petersburg 191186, Russia
[2] SAO RAS, SPB Branch, 65 Pulkovskoe Rd, St Petersburg 196140, Russia
[3] St Petersburg State Univ, Dept High Energy & Elementary Particles Phys, Univ Embankment 7-9, St Petersburg 199034, Russia