JETP Letters: issues online

The aim of this study is to set a baseline for the jet quenching measurements of the Quark Gluon Plasma formed in the large system size Nucleus-Nucleus (A-A) at top central collisions, via studying simulated small system size, Nucleon-Nucleon (N-N) collisions. The proton-proton (p-p) collisions were simulated using PYTHIA, at center of mass energies $\sqrt{s_{_{NN}}} = 200$ GeV and $\sqrt{s_{_{NN}}} = 13$ TeV corresponding to the available energies at the current collider experiments; the Relativistic Heavy Ion Collider, and the Large Hadron Collider. At both energies, the two-particle azimuthal correlation functions have been considered, and the yield associated with the high transverse momentum (p_{_T}) particles were extracted at its near-side ( $\Delta\phi \approx 0$ ) and away-side ( $\Delta\phi \approx \pi$ ) at mid pseudo rapidity ( $|\eta| \le 2$ ). The ratio between the near-side yields in the high multiplicity events to these of the low multiplicity events (I_{_HL}^{^N}), as well as, the ratio of the away-side yields (I_{_HL}^{^A}) were calculated at both energies as a function of the hadron fractional energy z_{_T} of the high-p_{_T} particle. At both energies, the values of I_{_HL}^{^N} and I_{_HL}^{^A} were less than unity, and of trivial dependence on z_{_T}. The values of I_{_HL}^{^A} are always less than these of I_{_HL}^{^N} at the same multiplicity and energy, and both quantities show a pattern of systematic decreases with the multiplicity. Such multiplicity dependence cannot be used neither to exclude the jet quenching nor to prove it in the high multiplicity events in p-p collisions, as the suppressions have been found at both sides, near and away of the high-p_{_T} particle.