Universality in High Energy Collisions of small and large systems

Abstract

Strangeness enhancement and collective flow are considered signatures of the quark gluon plasma formation. These phenomena have been detected not only in relativistic heavy ion collisions but also in high energy, high multiplicity events of proton-proton and proton-nucleus ("small systems") scatterings. A universal behavior emerges by considering the parton density in the transverse plane as the dynamical quantity to specify the initial condition of the collisions, which in + − annihilation at the available energies is too low to expect collective effects.

Initial- and Final-State Temperatures of Emission Source from Differential Cross-Section in Squared Momentum Transfer in High-Energy Collisions

“…As mentioned in the first section and discussed above, some distributions applied in a large collision system can be also applied in a small collision system due to the universality, similarity, or common characteristics existing in highenergy collisions [27][28][29][30][31][32][33][34][35][36]. Based on the same reason, some statistical or hydrodynamic models applied in the large system should be also applied in the small system.…”

Initial-State Temperature of Light Meson Emission Source From Squared Momentum Transfer Spectra in High-Energy Collisions

“…The relation between the two distributions is that the former one covers the later one in which the mass is neglected. Because the universality, similarity, or common characteristics exist in high-energy collisions [27][28][29][30][31][32][33][34][35][36], some distributions used in large collision system can be also used in small collision system. Although the equilibrium degree is also important, it is not discussed in this work due to other topics being concerned.…”

Initial-state temperature of light meson emission source from squared momentum transfer spectra in high-energy collisions

“…The relation between the two distributions is that the former one covers the later one in which the mass is neglected. Because the universality, similarity, or common characteristics exist in high-energy collisions [27][28][29][30][31][32][33][34][35][36], some distributions used in large collision system can be also used in small collision system. Although the equilibrium degree is also important, it is not discussed in this work due to other topics being concerned.…”