An exclusive measurement has been made of the Coulomb dissociation of the two-neutron halo nucleus 11Li at 70 MeV/nucleon at RIKEN. Strong low-energy (soft) E1 excitation is observed, peaked at about Ex = 0.6 MeV with B(E1) = 1.42(18) e2fm2 for Erel < or = 3 MeV, which was largely missed in previous measurements. This excitation represents the strongest E1 transition ever observed at such low excitation energies. The spectrum is reproduced well by a three-body model with a strong two-neutron correlation, which is further supported by the E1 non-energy-weighted cluster sum rule.

We theoretically show and experimentally verify that a pair of linearly polarized intense femtosecond pulses can create molecular ensembles with oriented rotational angular momentum on an ultrafast (approximately ps) time scale, when the delay and the mutual polarization between them are appropriately arranged. An asymmetric distribution for +M and -M sublevels relies on quantum interference between rotational wave packets created in stimulated Raman excitation by the first and second pulses. The present approach provides spatiotemporally propagating ensembles, of which the classical perspective is molecules rotating in a clockwise or counterclockwise direction.

We report on the multiphoton ionization processes in the soft-x-ray region ͑ഛ30 nm͒. On the basis of the measured time-of-flight spectra for both ions and electrons obtained using intense soft-x-ray pulses produced by high-order harmonics, the cross sections of the two-photon double ionization and above-threshold ionization of He are estimated. The high-intensity soft-x-ray radiation achieved by phase-matched high-order harmonics enables the investigation of these nonlinear optical processes, which were beyond the reach of conventional light sources.