T Tanabe, I Katayama, S Ono, K Chida, T Watanabe, Y Arakaki, Y Haruyama, M Saito, T Odagiri, K Hosono, K Noda, T Honma, H Takagi
Journal of Physics B 31 L297-L303 1998年2月22日
The dissociative recombinations of 3HeHC, 4HeHC, 3HeDC and 4HeDC were
studied with an extremely low-temperature electron beam of the order of 1 meV produced by
a superconducting electron cooler at the storage ring TARN II. The dissociative recombination
spectra show a fine new structure and a clear isotope dependence in the low-energy region.
Those features are well reproduced by the theoretical calculations based on a multichannel
quantum-defect theory including rotational motion and discretized dissociative states. According
to the theory, the newly observed structure is evidence for a new indirect mechanism where the
intermediate states are not vibrationally excited Rydberg states but virtual dissociative states.