Lifetime effects on the dissociation of core-excited N-2 and CO molecules - art. no. 022709

Vibrational-resolved ion and ion-pair yield spectra of N-2 and CO taken at their 1s --> pi* resonance excitations reveal decay-channel-dependent core hole lifetimes. The linewidths of the yield spectra tend to be shortened wh en the number of electrons ejected in the deexcitation process increases, f inally becoming narrower than the total ion yield or absorption natural lif etime width of the core-excited states of N-2 and CO, respectively. In cont rast to this, the linewidths of the yield spectra for the singly charged mo lecular ions, N-2(+) and CO+, are shown to be broader than their correspond ing natural linewidths. This linewidth shortening and broadening observed i n the ion yield spectra are explained by the effect of different internucle ar distances on the lifetime of an excited molecular state.