Enhancement of strong-field multiple ionization in the vicinity of the   conical intersection in 1,3-cyclohexadiene ring opening
  Nonradiative energy dissipation in electronically excited polyatomic molecules proceeds through conical intersections, loci of degeneracy between electronic states. We observe a marked enhancement of laser-induced double ionization in the vicinity of a conical intersection during a non-radiative transition. We measured double ionization by detecting the kinetic energy of ions released by laser-induced strong-field fragmentation during the ring-opening transition between 1,3-cyclohexadiene and 1,3,5-hexatriene. The enhancement of the double ionization correlates with the conical intersection between the HOMO and LUMO orbitals. 
Vladimir S. Petrovic, Sebastian Schorb, Jaehee Kim, James White, James   P. Cryan, J. Michael Glownia, Lucas Zipp, Douglas B...
physics.chem-ph physics.atm-clus quant-ph