https://doi.org/10.1140/epjd/e2005-00038-4
The dominant “heating” mode: bending excitation of water molecules by low-energy positron impact
Department of Chemistry and INFM, The University of
Rome “La Sapienza”, Piazzale A. Moro 5, 00185 Roma, Italy
Corresponding author: a fa.gianturco@caspur.it
Received:
13
December
2004
Revised:
17
February
2005
Published online:
12
April
2005
We report a quantum dynamical treatment of the vibrational excitation
of the bending mode of water molecules by collision with low energy positrons
in the energy regions close to threshold openings.
The exact vibrationally coupled-channel equations derived for the
total 
system are solved in a Body-Fixed-Vibrational-Coupled-Channels (BF-VCC) reference frame, using a single-center expansion of the total wavefunction and of the
interaction potential. The vibrationally inelastic cross-sections for
transitions from the ground to the lowest excited state of the bending mode clearly show
the bending excitation channel to be the dominant inelastic process at
low collision energies. Comparisons with our earlier calculations
for the other modes and for the excited processes induced by
electron impact are also presented and analysed.
PACS: 34.85.+x – Positron scattering / 34.90.+q – Other topics in atomic and molecular collision processes and interactions (restricted to new topics in section 34) / 34.80.-i – Electron scattering
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
