  We study numerically the phase behavior of self-propelled elliptical
particles interacting through the "hard" repulsive Gay-Berne potential at
infinite P\'eclet number. Changing a single parameter, the aspect ratio, allows
to continuously go from discoid active Brownian particles to elongated polar
rods. Discoids show phase separation, which changes to a cluster state of polar
domains, which then form polar bands as the aspect ratio is increased. From the
simulations, we identify and extract the two effective parameters entering the
mean-field description: the force imbalance coefficient and the effective
coupling to the local polarization. These two coefficients are sufficient to
obtain a complete and consistent picture, unifying the paradigms of scalar and
polar active matter.
