Scaling Behavior Of The Transverse Momentum Spectra Of P-Pb Under 5.02TeV Collision

There are a large number of final particles in high energy collisions.Investigating the dynamics of particle productions is one of the main goals in high energy collisions.The transverse momentum spectra of final state particles are significant observables in high energy collisions.In many studies,searching for a universal scaling of the spectra versus suitable variables has been utilized to reveal the dynamics of particle productions.In this paper,we systematically investigate the scaling property of nesons(pion and kaon)and baryons(proton,?,? and Q)pT spectra at seven different centralites(0-5%,5-10%,10-20%,20-40%,40-60%,60-80%and 80-100%)in proton-lead(p-Pb) collisions with center of mass energy per nucleon pair((?))5.02 TeV.When the pion(kaon,proton,A,? and ?)transverse momentum spectra are expressed in a variable z?pT/K,we find that in the small transverse momentum region with pT?3.9(3.1,2.5,2.7,2.4 and 2.8)GeV/c,the spectra of mesons and baryon present a universal scaling independent of the centrality of the collisions.Here K is a scaling paraleter depending on the centrality,its value is determined by the quality factor method and is parameterized by a<Npart>b,a and b are two parameter,b represents the rate at which InK changes with the logarithmic value of the average value of the number of participating nucleons In<Npart>.The b values are stronger for baryons than those for mesons.In the high pT region,there is a departure of the scaling.The more peripheral the collisions are,the more apparently the scaling is spoiled.In the Colour String Percolation(CSP)model,mesons and baryons are generated from the decay of clusters formed by the colour strings overlapping with the same size dispersion but with different mean size.The mean size of clusters for baryons is smaller than that of mesons.For the same hadrons at different centrality classes,the mean size of clusters decreases with the increase of centrality.In addition,the fragmentation functions for cluster decay are different for different hadrons,while they are universal for the same hadrons at different centrality classes.We find that the universal scaling of the meson and baryon spectra in the low pT region can be quantitatively understood with the CSP model at the same time.