Exploring differential two-particle correlations in γ p and low-multiplicity p p collisions using pythia8

A study of two-particle differential number ( B ) and transverse momentum ( P 2 CD ) balance functions in photon-proton ( γ p ) and proton-proton (pp) collisions at s = 5.36 TeV is presented. The analysis focuses on inclusive charged hadrons within the pseudorapidity coverage | η | < 2.4 and the transverse momentum interval 0.3 < p T < 3.0 GeV and examines their correlations in terms of relative pseudorapidity ( Δ η ) and relative azimuthal angle ( Δ ϕ ). The correlation functions are evaluated for same- and opposite-sign pairs, and their combinations are used to extract charge-dependent (CD) and charge-independent (CI) components. The evolution of the nearside peak of the CD correlations is investigated in terms of Δ η and Δ ϕ as a function of charged-particle multiplicity ( N ch ) for γ p collisions and compared to pp collisions at a similar multiplicity range. A clear multiplicity dependence of the balance-function width is obtained. The width is found systematically lower in γ p events than in pp collisions. This study provides valuable information on particle correlations and production mechanisms in low- N ch regimes for upcoming measurements in small systems.