Left panel: Normalized differential primary charged particle yield in NSD $pp$ collisions at $\sqrt{s}=900 $GeV, averaged in $|\eta|< 0.8$ The ALICE data are compared to results from ATLAS and CMS in $pp$ at the same energy [19,20] Right panel:Normalized invariant primary charged particle yield in NSD $pp$ collisions at $\sqrt{s}=900 $GeV, averaged in $|\eta|< 0.8$ The ALICE data are compared to results from UA1 in$p\bar{p}$ at the same energy [21]. For the computation of the invariant yield, it has been assumed that all particles are pions The shaded areas indicate the statistical and systematic errors added in quadrature.