  In recent years, significant progress has been made in the computation of
conservative and dissipative scattering observables using the post-Minkowskian
approach to gravitational dynamics. However, for accurate modeling of unbound
orbits, an appropriate effective-one-body (EOB) resummation of the
post-Minkowski results that also accounts for dissipative dynamics is
desirable. As a step in this direction, we consider the electromagnetic analog
of this problem here. We show that a six-parameter equation of motion
encapsulates the effective-one-body dynamics for the electromagnetic scattering
problem appropriate to third-order in the coupling constant. Three of these six
parameters describe the conservative part of the dynamics, while the rest
correspond to the radiation-reaction effects. Here we show that only two
radiation-reaction-related parameters are important at the desired order,
making the effective number of parameters in our formalism to be five. We
compute the explicit forms of these five parameters by matching EOB scattering
observables to that of the original two-body ones computed by [Saketh et al.,
Phys.Rev.Res. 4 (2022) 1]. Interestingly, our formalism leads to a conjecture
for the sub-leading angular momentum loss, for which no precise computations
exist. In addition, we demonstrate that the bound-orbit observables computed
using our method are in perfect agreement with those calculated using
unbound-to-bound analytical continuation techniques. Lastly, we qualitatively
discuss the extension of our formalism to gravity.
