  The stochastic dynamics of an active particle undergoing a constant speed and
additionally driven by an overall fluctuating torque is investigated. The
random torque forces are expressed by a stochastic differential equation for
the angular dynamics of the particle determining the orientation of motion. In
addition to a constant torque, the particle is supplemented by random torques
which are modeled as an Ornstein-Uhlenbeck process with given correlation time
$\tau_c$. These nonvanishing correlations cause a persistence of the particles'
trajectories and a change of the effective spatial diffusion coefficient. We
discuss the mean square displacement as a function of the correlation time and
the noise intensity and detect a nonmonotonic dependence of the effective
diffusion coefficient with respect to both correlation time and noise strength.
A maximal diffusion behavior is obtained if the correlated angular noise
straightens the curved trajectories, interrupted by small pirouettes, whereby
the correlated noise amplifies a straightening of the curved trajectories
caused by the constant torque.
