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 (\(v_n\)) are sensitive to the initial-state effects including nuclear shape, deformation, and charge density profiles, studies involving \(^{12}\)C and \(^{16}\)O nuclei are transpiring due to the presence of exotic \(\alpha\) (\(^{4}\)He) clusters in such nuclei. In this study, for the first time, we investigate the effects of nuclear \(\alpha\)--clusters on the azimuthal anisotropy of the final-state hadrons in p--C and p--O collisions at \(\sqrt{s_{\rm NN}}= 9.9\) TeV within a multi-phase transport model framework. We report the transverse momentum (\(p_{\rm T}\)) and pseudorapidity (\(\eta\)) spectra, participant eccentricity (\(\epsilon_2\)) and triangularity (\(\epsilon_3\)), and estimate the elliptic flow (\(v_2\)) and triangular flow (\(v_3\)) 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 \(^{12}\)C and \(^{16}\)O nuclei.