  Propagation of ion-acoustic solitary waves (IASWs) is studied using the
hydrodynamic equations coupled with the Poisson equation in a warm plasma
consisting of adiabatic ions and superthermal (Kappa distributed) electrons in
presence of an electron-beam component. In the linear limit, the dispersion
relation for ion-acoustic (IA) waves is obtained by linearizing of basic
equations. On the other hand, in the nonlinear analysis, an energy-balance like
equation involving Sagdeev's pseudo-potential is derived in order to
investigate arbitrary amplitude IA solitons. The Mach number range is
determined in which, propagation and characteristics of IA solitons are
analyzed both parametrically and numerically. The variation of amplitude and
width of electrostatic (ES) excitations as a result of superthermality (via)
and also the physical parameters (ion temperature, soliton speed, electron-beam
density and electron-beam velocity) are examined. A typical interaction between
IASWs and the electron-beam in plasma is confirmed. It is also found that ES
solitons with both negative polarity (rarefactive solitons) and positive
polarity (compressive solitons) can coexist in plasma. Furthermore, the small
but finite amplitude limit of IASWs is investigated and it is showed that this
limit is restricted to negative potential pulses.
