  In the previous canonical formulation of beam dynamics for an electron bunch
moving ultrarelativistically through magnetic bending systems, we have shown
that the transverse dynamics equation for a particle in the bunch has a driving
term which behaves as the centrifugal force caused by the particle's initial
potential energy due to collective particle interactions within the bunch. As a
result, the initial potential energy at the entrance of a bending system, which
we call pseudo (kinetic) energy, is indistinguishable from the usual kinetic
energy offset from the design energy in its perturbation to particle optics
through dispersion and momentum compaction. In this paper, in identifying this
centrifugal force on particles as the remnant of the CSR cancellation effect in
transverse particle dynamics, we show how the dynamics equation in terms of the
canonical momentum for beam motion on a curved orbit is related to the
Panofsky-Wenzel theorem for wakefields for beam motion on a straight path. It
is shown that the effect of pseudo energy spread can be measurable only for a
high-peak-current bunch when the pseudo slice energy spread is appreciable
compared to the slice kinetic energy spread. The implication of the pseudo
slice energy spread for bunch dynamics in magnetic bends is discussed.
