  Using the explicit numerical solution of the axially-symmetric
Gross-Pitaevskii equation we study the dynamics of interaction among vortex
solitons in a rotating matter-wave bright soliton train in a radially trapped
and axially free Bose-Einstein condensate to understand certain features of the
experiment by Strecker et al.[2002 Nature 417 150]. In a soliton train,
solitons of opposite phase (phase delta = pi) repel and stay apart without
changing shape; solitons with delta = 0 attract, interact and coalesce, but
eventually come out; solitons with a general delta usually repel but interact
inelastically by exchanging matter. We study and suggest future experiments
with vortex solitons.
