Observation Of Increasing Charged Multiplicity As A Function Of Transverse-Momentum In P + P-]Pi+ + Mm At 28.5 Gev/C

We have measured the mean charged multiplicity ${\overline{n}}_{c}$ as a function of the transverse momentum ${p}_{\ensuremath{\perp}}$ of a forward ${\ensuremath{\pi}}^{+}$ meson for fixed missing mass MM in the reaction $p+p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}+\mathrm{MM}$ using the multiparticle Argo spectrometer system. We observe an increase similar to that seen in $p+p\ensuremath{\rightarrow}p+\mathrm{MM}$ at the same incident energy.