Far-wing excitation study on the transition regions of the metastable mercury atom collisions: Hg(63P2) + N2 and CO

We have measured the c̃–X̃ laser excitation spectra of the Hg–N2 and CO collisional quasimolecules for the formation of Hg(63P2) and Hg(63P1) in the far wings of the Hg 61S0–63P2 dipole-forbidden line. These are the first observations of the c̃–X̃ bands in Hg–molecule systems. It is found that Hg(63P1) is efficiently produced via a nonadiabatic transition from the c̃ state. This is in striking contrast with the Hg–rare gas cases where no nonadiabatic processes have been observed.