  We treat the question of bottomonia suppression in ultrarelativistic heavy
ion collisions (URHIC) as a dynamical open quantum problem, tackled for the
first time using the Schr\"odinger-Langevin equation. Coupling this equation to
the EPOS2 event generator, predictions are made for the nuclear modification
factor of $\Upsilon (1S)$ and $\Upsilon (2S)$.
