  In p-p collisions, the produced charge particles consist of two leading
particles and those frozen out from the hot and dense matter created in
collisions. The two leading particles are respectively in the projectile and
target fragmentation region, which, in this paper, are conventionally supposed
to have Gaussian rapidity distributions. The hot and dense matter is assumed to
expand according to the unified hydrodynamics, a hydro model which unifies the
features of Landau and Hwa-Bjorken model, and freeze out into charged particles
from a space-like hypersurface with a fixed proper time of Tau_FO. The rapidity
distribution of this part of charged particles can be derived out analytically.
The combined contribution from both leading particles and unified hydrodynamics
is then compared against the experimental data performed in a wide now
available center-of-mass energy region from 23.6 to 7000 GeV. The model
predictions are in well consistent with experimental measurements.

Nuclear Theory