Two-body Coulomb explosion and hydrogen migration in methanol induced by intense 7 and 21 fs laser pulses

Itakura, Ryuji; Liu, P.*; Furukawa, Yusuke*; Okino, Tomoya*; Yamanouchi, Kaoru*; Nakano, Hidetoshi*

Coulomb explosion of methanol induced by intense laser pulses with t = 7 and 21 fs is investigated by coincidence momentum imaging. When t = 7, the angular distribution of recoil vectors for the direct C-O bond breaking exhibits a peak deflected from the laser polarization direction by 30-45 deg., and the corresponding angular distribution for the migration pathway exhibits almost the same profile. When the laser pulse is stretched to t = 21 fs, the angular distributions for the direct and migration pathways exhibit a broad peak along the laser polarization direction. However, the extent of the anisotropy in the migration pathway is smaller than that in the direct pathway, exhibiting a substantial effect of hydrogen atom migration.