Binary and recoil collisions in strong field double ionization of helium

We have investigated the correlated momentum distribution of both electrons from nonsequential double ionization of helium in a 800 nm, 4.5 71014W/cm2 laser field. Using very high resolution coincidence techniques, we find a so-far unobserved fingerlike structure in the correlated electron momentum distribution. The structure can be interpreted as a signature of the microscopic dynamics in the recollision process. We identify features corresponding to the binary and recoil lobe in field-free (e,2e) collisions. This interpretation is supported by analyzing ab initio solutions of a fully correlated three-dimensional helium model. \ua9 2007 The American Physical Society.Peer reviewed: YesNRC publication: Ye

Photoelectron and ICD electron angular distributions from fixed-in-space neon dimers

We report on molecular frame angular distributions of 2s photoelectrons and electrons emitted by interatomic Coulombic decay from neon dimers. We found that the measured angular distribution of the photoelectron strongly depends on the environment of the cluster. The experimental results are in excellent agreement with frozen core Hartree\u2013Fock calculations. The ICD electrons show slight variations in their angular distribution for different kinetic energies.Peer reviewed: YesNRC publication: Ye

Experimental separation of virtual photon exchange and electron transfer in interatomic Coulombic decay of neon dimers

We investigate the interatomic Coulombic decay (ICD) of neon dimers following photoionization with simultaneous excitation of the ionized atom (shakeup) in a multiparticle coincidence experiment. We find that, depending on the parity of the excited state, which determines whether ICD takes place via virtual dipole photon emission or overlap of the wave functions, the decay happens at different internuclear distances, illustrating that nuclear dynamics heavily influence the electronic decay in the neon dimer.Peer reviewed: YesNRC publication: Ye

Identifying gene-environment interactions in schizophrenia: Contemporary challenges for integrated, large-scale investigations

Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G 7 E), however, so far, thorough replication of findings is rare and G 7 E research still faces several conceptual and methodological challenges. In this article, we aim to review these recent developments and illustrate how integrated, large-scale investigations may overcome contemporary challenges in G 7 E research, drawing on the example of a large, international, multi-center study into the identification and translational application of G 7 E in schizophrenia. While such investigations are now well underway, new challenges emerge for G 7 E research from late-breaking evidence that genetic variation and environmental exposures are, to a significant degree, shared across a range of psychiatric disorders, with potential overlap in phenotype. \ua9 2014 The Author