[1] Vilnius Univ, Inst Theoret Phys & Astron, LT-10222 Vilnius, Lithuania
[2] Ruhr Univ Bochum, Inst Theoret Phys 2, D-44870 Bochum, Germany
[3] Univ Lisbon, Ctr Fis Nucl, P-1649003 Lisbon, Portugal
[4] Leibniz Univ Hannover, D-30167 Hannover, Germany