  High sensitivity searches of globular clusters (GC) for radio pulsars by
improved pulsar search algorithms and sustained pulsar timing observations have
so far yielded some 140 pulsars in more than two dozen GCs. The observed
distribution of orbital eccentricity and period of binary radio pulsars in GCs
have imprints of the past interaction between single pulsars and binary systems
or of binary pulsars and single passing non-compact stars. It is seen that GCs
have different groups of pulsars. These may have arisen out of exchange or
merger of a component of the binary with the incoming star or a "fly-by" in
which the original binary remains intact but undergoes a change of eccentricity
and orbital period. We consider the genesis of the distribution of pulsars
using analytical and computational tools such as STARLAB, which performs
numerical scattering experiments with direct N-body integration. Cluster
pulsars with intermediate eccentricities can mostly be accounted for by fly-bys
whereas those with high eccentricities are likely to be the result of exchanges
and/or mergers of single stars with the binary companion of the pulsar,
although there are a few objects which do not easily fit into this description.
The corresponding distribution for galactic field pulsars shows notable
differences from the GC pulsar orbital period and eccentricity distribution.
The long orbital period pulsars in the galactic field with frozen out low
eccentricities are largely missing from the globular clusters, and we show that
ionization of these systems in GCs cannot alone account for the peculiarities.
