Role of clustered nuclear geometry in particle production through p-C and p-O collisions at the Large Hadron Collider

Long-range multi-particle correlations in heavy-ion collisions have shown conclusive evidence of the hydrodynamic behavior of strongly interacting matter, and are associated with the final-state azimuthal momentum anisotropy. In small collision systems, azimuthal anisotropy can be influenced by the hadronization mechanism and residual jet-like correlations. Thus, one of the motives of the planned p--O and O--O collisions at the LHC and RHIC is to understand the origin of small system collectivity. As the anisotropic flow coefficients (vₙ) are sensitive to the initial-state effects including nuclear shape, deformation, and charge density profiles, studies involving ¹²C and ¹⁶O nuclei are transpiring due to the presence of exotic α (⁴He) clusters in such nuclei. In this study, for the first time, we investigate the effects of nuclear α--clusters on the azimuthal anisotropy of the final-state hadrons in p--C and p--O collisions at √sNN= 9.9 TeV within a multi-phase transport model framework. We report the transverse momentum (pT) and pseudorapidity (η) spectra, participant eccentricity (ε₂) and triangularity (ε₃), and estimate the elliptic flow (v₂) and triangular flow (v₃) of the final-state hadrons using the two-particle cumulant method. These results are compared with a model-independent Sum of Gaussians (SOG) type nuclear density profile for ¹²C and ¹⁶O nuclei.