Single photon induced symmetry breaking of H2 dissociation

H{sub 2}, the smallest and most abundant molecule in the universe, has a perfectly symmetric ground state. What does it take to break this symmetry? Here we show that the inversion symmetry can be broken by absorption of a linearly polarized photon, which itself has inversion symmetry. In particular, the emission of a photoelectron with subsequent dissociation of the remaining H{sub 2}{sup +} fragment shows no symmetry with respect to the ionic H+ and neutral H atomic fragments. This result is the consequence of the entanglement between symmetric and antisymmetric H{sub 2}{sup +} states resulting from autoionization. The mechanisms behind this symmetry breaking are general for all molecules

Dynamics Of Multiply Charged Ion-atom Collisions: U³²⁺+Ne

Measurements and calculations are presented for the mean recoil-ion energies of Nei+ produced in 1.4 MeV u-1 (0.33 GeV) collisions of U32+ with Ne. Recoil-ion charge states i=1-8 have been observed; the mean recoil energies are low and do not exceed 1 eV until i\u3e6. Calculations employing a newly developed n-body classical trajectory Monte Carlo method are found to yield results in qualitative agreement with the recoil-ion experiment. Calculations also are presented for the ionisation and charge exchange cross sections, the projectile energy loss and the ejected-electron energy and angular spectra. The importance of fast ejected electrons in the dynamics of energetic multiply charged ion-atom collisions is noted

Three-body final-state momentum distributions for swift H+H^+ and He2+He^{2+} on He collisions

The transverse and longitudinal momentum distributions of He+ions produced by 0.25-1MeV u-1H+ and He2+impact have been measured using a precooled supersonic gas jet target (cold-target recoil ion-momentum spectroscopy—coltrims). The transverse momentum of the recoil ions is mainly determined by the impact parameter. In the longitudinal direction the recoil ions are slightly backwardly directed. The width of the longitudinal momentum distribution is close to the electron momentum distribution in the initial state. This distribution gets much broader for larger transverse momentum transfer (i.e. smaller impact parameters). The experimental results are in good agreement with nCTMC calculations. © 1995 IOP Publishing Ltd