[1] Univ Ulm, Abt Quantenphys, D-89069 Ulm, Germany
[2] Weizmann Inst Sci, Dept Chem Phys, IL-76100 Rehovot, Israel
[3] Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico
[4] Univ Toulouse 3, CNRS, Lab Collisions Agregats & React, UMR 5589,IRSAMC, Toulouse, France
[5] Univ Ulm, Abt Zahlentheorie & Wahrscheinlichkeitstheorie, D-89069 Ulm, Germany
[6] Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA