Volume 77, Number 3, February 2007
Article Number 33001
Number of page(s) 6
Section Atomic, Molecular and Optical Physics
Published online 01 February 2007
EPL, 77 (2007) 33001
DOI: 10.1209/0295-5075/77/33001

Quenching of vibrationally excited molecules by ultracold collisions with ions: Controlling the scattering via changes of internal states

E. Bodo and F. A. Gianturco

Dipartimento di Chimica and CNISM, Università di Roma "La Sapienza" - P.le A. Moro 5, 00185, Roma, Italy

received 16 October 2006; accepted in final form 29 November 2006; published February 2007
published online 1 February 2007

Inducing low-energy p-wave resonances by an additional external electric field has been shown recently to be a possible way of controlling ultra-low energy atomic collisions (KREMS R. V., Phys. Rev. Lett., 96 (2006) 123202). We show here by calculation that also in molecular systems with long-range interactions there exist internal states for which a low energy p-wave resonance is clearly contributing to the scattering even at ultra-low energies, and that for this collisional regime the scattering length turns out to be positive. We thus present results for the vibrational relaxation cross-sections of H2, prepared in different vibrational states, in collision with ${\rm Li}^{+}$ in that energy regime and examine the changes in scattering attributes, both in the elastic and inelastic channels, when the internal vibrational state of H2 is modified.

34.50.Lf - Chemical reactions, energy disposal, and angular distribution, as studied by atomic and molecular beams .
34.20.Mq - Potential energy surfaces for collisions.

© Europhysics Letters Association 2007