  In this work we report the detection of seven Neptune Trojans (NTs) in the
Pan-STARRS 1 (PS1) survey. Five of these are new discoveries, consisting of
four L4 Trojans and one L5 Trojan. Our orbital simulations show that the L5
Trojan stably librates for only several million years. This suggests that the
L5 Trojan must be of recent capture origin. On the other hand, all four new L4
Trojans stably occupy the 1:1 resonance with Neptune for more than 1 Gyr. They
can, therefore, be of primordial origin. Our survey simulation results show
that the inclination width of the Neptune Trojan population should be between
$7^{\circ}$ and $27^{\circ}$ at $>$ 95% confidence, and most likely $\sim
11^{\circ}$. In this paper, we describe the PS1 survey, the Outer Solar System
pipeline, the confirming observations, and the orbital/physical properties of
the new Neptune Trojans.
