Ultrafast Relaxation Dynamics of Uracil Probed via Strong Field Dissociative Ionization

We study the ultrafast relaxation
dynamics of uracil excited to
the first bright ππ* state (S2) by an ultrafast
laser pulse in the deep ultraviolet (central wavelength λ0 = 260 nm). With a unique combination of strong field dissociative
ionization measurements, state of the art strong field ionization
calculations, and high level ab initio calculations of excited neutral
and ionic states at critical points along the neutral potentials,
we are able to gain a detailed picture of the relaxation dynamics
of the molecule, which resolves earlier disagreements regarding measurements
and calculations of the relaxation.