中国物理学会高能物理分会第十三届全国粒子物理学术会议（2021）

We investigate the identified hadrons transverse momentum ($p_T$) spectra in proton-proton (pp) collisions at 0.9, 2.76, 5.02, 7 and 13 TeV in the framework of Tsallis-blast wave (TBW) model. In this model, the Tsallis temperature and the average radial flow velocity of the system are common for all hadrons, while the degrees of non-equilibrium are common to all of the mesons and baryons respectively when a combined fit is performed to the pT spectra of different particles at a given energy. It is found that the model can describe the particle spectra well up to 10 GeV/c. The transverse flow velocity as well as the degree of non-equilibrium increases with the center of mass energy, while the Tsallis temperature first increases with energy up to 2.76 TeV and then saturates around 86 MeV. We also extend this model to the identified particle spectra at different charged particle multiplicities in pp collisions at 7 TeV and 13 TeV. It is observed that the radial flow increases with the multiplicity while the degree of non-equilibrium shows the opposite behavior, which is similar to that observed in Pb-Pb and p-Pb collisions at the LHC energy. However, the Tsallis temperature decreases with the multiplicity, which is opposite to the trend observed in Pb-Pb and p-Pb collisions. We proposed a possible explanation for this behaviour. Finally, at similar charged multiplicities, the radial flow in Pb-Pb and p-Pb collisions is smaller than that in pp collisions, which indicates that the size of the colliding system might have significant effects on the final state particle dynamics.