Longitudinal flow decorrelation in heavy-ion collision at RHIC energies using a multi-phase transport model

We present a study on the longitudinal flow decorrelation in heavy-ion collisions at the RHIC Beam Energy Scan (BES) energies ([Formula: see text] = 11.5 to 200 GeV in Au+Au collisions) using the AMPT model. We measure the factorization ratios of the second and third order flow harmonics ([Formula: see text] and [Formula: see text]) across BES energies. Within the present statistical uncertainties, the results suggest a possible increase in longitudinal decorrelation toward lower collision energies, with triangular flow showing a comparatively stronger sensitivity than elliptic flow. The final-state longitudinal decorrelation is found to be smaller than the initial-state eccentricity decorrelation, indicating the dynamical establishment of longitudinal correlations during the system evolution. While elliptic flow decorrelation shows sensitivity to the partonic interaction strength, the triangular component appears largely insensitive within the explored range. We also analyze the contributions of flow-plane and flow magnitude decorrelation, and see that flow-plane decorrelation is dominant in BES energies. Finally, we measure a recently proposed observable, the four particle cumulant ([Formula: see text]), which remains resilient to non-flow effects and exhibits sensitivity to different decorrelation patterns. But in central and mid-central collisions, presence of any specific pattern of decorrelation is missing in AMPT model, which is consistent with a scenario of random orientation of event plane in rapidity windows.