Test of predictedΔn≥1L-shell dielectronic-recombination cross sections

The predicted charge-state dependence of dielectronic-recombination cross sections involving Δn>=1 L-shell excitation has been tested by measurements of resonant transfer and excitation (RTE) for ${}_{41}{}^{}{}_{}{}^{}\mathrm{Nb}_{}^{\mathrm{q}+}{}_{}{}^{}$+${\mathrm{H}}_2$ (q=28 to 32) collisions at 3.7 and 4.0 MeV/u. The measured RTE cross sections increase significantly with increasing charge state and thus disagree substantially with theoretical calculations that predict essentially equal cross sections for ${\mathrm{Nb}}^{29+}$, ${\mathrm{Nb}}^{30+}$, and ${\mathrm{Nb}}^{31+}$. This disagreement is contrary to the good agreement previously found between theory and experiment for K-shell RTE.