  We consider the excitation of single-electron wave packets by means of a time
dependent voltage applied to the ballistic edge channels of the integer quantum
Hall effect at filling factor $\nu=2$. Due to electron-electron interactions,
fractional excitations emerge along the edge. Their detailed structure is
analyzed by evaluating the nonequilibrium momentum distributions associated
with the different edge channels. We provide results for a generic
time-dependent drive both in the stationary regime and for intermediate times,
where the overlap between fractionalized wave packets carries relevant
information on interaction strength. As a particular example we focus on a
Lorentzian drive, which provides a clear signature of the minimal excitations
known as Levitons. Here, we argue that inner-channel fractionalized excitations
can be exploited to extract information about inter-channel interactions. We
further confirm this idea by calculating the zero frequency noise due to the
partitioning of these excitations at a quantum point contact and we propose a
measurable quantity as a tool to directly probe electron-electron interactions
and determine the so-called mixing angle of copropagating quantum Hall
channels.
