Rotational de-excitation of hydrogen–helium muonic molecules in non-ionizing collisions with hydrogen atoms

Abstract

Rotational J = 1 → J = 0 transitions in muonic molecules (3Heμh)++J, in the process (3Heμh)++1 + H → (3Heμh)++0 + H, where h = p, d, t; H is the respective hydrogen isotope atom (H, D, T) and μ = μ− (the negative muon), are investigated. The corresponding cross sections and reaction rates are calculated for collision energies 0.001–0.5 eV in the frame of the distorted-wave Born approximation method using the Born–Oppenheimer approximation for a two-centre wavefunction of the hydrogen atom electron. The results obtained for transition rates, normalized to the liquid hydrogen density, are relatively small and range between 102 s−1 and 103 s−1 for (3Heμp)++1 − H and (3Heμd)++1 − D, whereas for (3Heμt)++1 − T they range between 103 s−1 and 104 s−1. They are about 6–8 orders of magnitude smaller than reaction rates for the 1 → 0 de-excitation induced by the hydrogen atom ionization considered in our previous paper (Czapliński et al 2008 J. Phys. B: At. Mol. Phys. 41 035101).