Exploring Event-by-Event pT Fluctuations in pp Collisions at √s = 13 TeV: An Insight from ALICE

Event-by-event fluctuations of the mean transverse momentum (pT) of relativistic charged particles are analyzed using the two-particle correlator √Cₘ/M(pT)ₘ, which quantifies the correlations strength in units of the mean pT in proton-proton collision at √s = 13 TeV in ALICE both for minimum bias and and high-multiplicity triggered events. The non-monotonic variations in pT correlations with changing energy could serve as a signature of QGP formation. A comprehensive investigation across soft-, intermediate-, and hard-pT regions could provide crucial insights into both equilibrium (e.g., thermal radial flow) and non-equilibrium (e.g., jet/minijet) contributions to pT fluctuations. The dependence of the correlator on particle multiplicity for different pT window widths and positions is explored. The correlator values are found to decrease with increasing charged particle density, following a power-law behavior similar to observations in both small and large systems at lower energies. Additionally, the influence of pT range on the power-law coefficient is studied and results are compared with predictions from Monte Carlo models, such as PYTHIA (pQCD string model) and EPOS (core-corona model), to enhance understanding of the underlying mechanisms driving pT fluctuations.