Scaling and multiplicity dependence of pT spectra in pp collisions at

With the experimental data from STAR on the multiplicity dependence of the transverse momentum spectra of charged particles in pp collisions at , we investigate the scaling property of the spectra in those collisions. Using the scaling functions of pion and proton obtained in studying spectra in Au + Au and d + Au collisions, we describe the charged particle pT spectra in pp collisions as a superposition of those from pion and proton. Species contents are obtained and p/π ratio is given as a function of pT for events with some given charged multiplicities.