x , it is a transient increase. Therefore, we attribute this channel to the secondary dissociation of the larger ions, eventually ending up with the smallest CH + x fragment. We can denote this channel as (1, 0) → (1, 1, 0)/(1, 0, 0) (Figure ), meaning that after probing, three fragments are produced, either two monocations and one neutral, or one monocation and two neutrals. The slow transient lifetimes could be attributed to the relaxation lifetimes of the vibrationally and vibronically excited fragment ions that eventually fragment further upon the interaction with the probe pulse, leading to transient decay of its own ion yield and corresponding transient increase in the ion yield of the CH + x species. Such fragmentation is consistent with observations from the static recoil-frame covariance analysis, which demonstrates secondary fragmentation patterns (see Section 3.2.3).