  We study the dynamics of one-dimensional active particles confined in a
double-well potential, focusing on the escape properties of the system, such as
the mean escape time from a well. We first consider a single-particle both in
near and far-from-equilibrium regimes by varying the persistence time of the
active force and the swim velocity. A non-monotonic behavior of the mean escape
time is observed with the persistence time of the activity, revealing the
existence of an optimal choice of the parameters favoring the escape process.
For small persistence times, a Kramers-like formula with an effective potential
obtained within the Unified Colored Noise Approximation is shown to hold.
Instead, for large persistence times, we developed a simple theoretical
argument based on the first passage theory which explains the linear dependence
on the escape time with the persistence of the active force. In the second part
of the work, we consider the escape of two active particles mutually repelling.
Interestingly, the subtle interplay of active and repulsive forces may lead to
a correlation between particles favoring the simultaneous jump across the
barrier. This mechanism cannot be observed in the escape process of two passive
particles. Finally, we find that, in the small-persistence regime, the
repulsion favors the escape, like in passive systems, in agreement with our
theoretical predictions, while for large persistence times, the repulsive and
active forces produce an effective attraction which hinders the barrier
crossing.
