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A: Fachverband Atomphysik
A 26: Electron Scattering and Recombination / Interaction of Matter with Ions (with MO)
A 26.7: Vortrag
Freitag, 12. März 2010, 12:30–12:45, B 302
Collisions of low-energy antiprotons with He atoms — •Armin Lühr and Alejandro Saenz — Humboldt-Universität zu Berlin, Institut für Physik, Moderne Optik, Hausvogteiplatz 5-7, D-10117 Berlin
During the last two decades advances have been achieved in the understanding of antiproton (p) collisions with the simplest one- and two-electron atoms H and He. However, in the case of p + He experiment and theory did not agree for impact velocities below the mean electron velocity for more than a decade stimulating a vivid theoretical activity.
Theoretical investigations for collisions of p with helium atoms in an energy range from 1 keV to 6 MeV have been performed. The He atom is described with a full two-electron approach which was recently applied in nonperturbative time-dependent calculations of p + H2 collisions [1]. The scattering wave function is expanded in time-independent eigenstates of the target. The impact-parameter method is employed to describe the collision process. The present results for excitation and ionization are compared to experimental as well as theoretical data highlighting persisting inconsistencies among these data. The influence of two-electron effects as well as of expansion parameters on the outcome of the calculations is discussed.
[1] A. Lühr and A. Saenz, Phys. Rev. A 80, (Rapid Communication) (2009)