Azimuthal Two-Particle Correlations as a Probe of Colour String Fusion in p + p Collisions

In this paper, we explore the potential of the colour string model with fusion to describe the azimuthal correlations in proton-proton collisions at \(\sqrt s = 13\) TeV. Our approach is based on a detailed simulation of the longitudinal and transverse dynamics of strings leading to their subsequent fusion and decay. The azimuthal anisotropy appears due to a momentum loss that particles exhibit once they pass through the non-uniform strings’ density. We calculate two-particle correlation function \(C(\Delta \eta ,\Delta \phi )\), corresponding \({{c}_{2}}\{ 2\} \) cumulant and \({{v}_{2}}\{ 2\} \) Fourier harmonic by two methods. Results reveal an event multiplicity dependency of these observables, while multi-particle correlations are not induced by the string fusion mechanism.