On complete submanifolds with parallel mean curvature in product spaces
  We prove a Simons type formula for submanifolds with parallel mean curvature vector field in product spaces of type $M^n(c)\times\mathbb{R}$, where $M^n(c)$ is a space form with constant sectional curvature $c$, and then we use it to characterize some of these submanifolds. 
Dorel Fetcu and Harold Rosenberg
math.DG