Phenomenological Approach to Multiple Particle Production

We formulate empirically the rapidity density distribution of produced particles in multiple particle production. The assumed mechanism is that the produced particles are emitted isotropically from several emitting centers, located on the rapidity axis. The formula includes five adjustable parameters, which are to be determined by the experimental data of (pseudo-)rapidity density distributions and transverse momentum distributions at various energies. It is a distinguished difference of the present rapidity density distribution from those of other models that the particle production is suppressed strongly in the forward region. We discuss multiplicity and inelasticity at high energies, the pseudo-rapidity density distribution at LHC energy and some speculations, based on the present formulation.