Collision-induced torque mediates transition of dynamic patterns formed by active particles

It is still challenging to control dynamic self-organization patterns of self-propelled particles. Although varieties of patterns associated with chirality have been observed, essential control factors determining patterns remain unclear. Here, we explore numerically how torque upon particle collision affects dynamic self-organization. Based on the particle-based model with both collision-induced torque and torque in self-propulsion, we find that introducing collision-induced torque turns homogeneous bi-polar orientation templated by bi-directional alignment into rotating mono-polar flocks.