Kinematically complete experiment on transfer excitation in intermediate-energy $p+\mathrm{He}$ collisions

We have performed a kinematically complete experiment on transfer excitation in intermediate-energy proton-helium collisions. The differential cross sections were compared to double excitation data and a nonperturbative time-dependent calculation. This comparison reveals the importance of dynamic couplings between the motion of the heavy nuclei and electronic transitions and/or electron-electron correlation effects.

Figure 1

Transverse versus longitudinal recoil-ion momentum distribution in $25\mathrm{keV}$ $p+\mathrm{He}$ collisions. The intensity is plotted on a logarithmic scale.

Figure 2

Differential transfer-excitation cross sections as a function of scattering angle for 25, 50, and $75\mathrm{keV}$ $p+\mathrm{He}$. The solid lines show nonperturbative time-dependent calculations based on the basis generator method.

Figure 3

Ratio between transfer-excitation to single capture and double to single excitation cross-section ratios as a function of scattering angle. Solid line as in Fig. 2, but different screenings were used for the various processes.