Hawking radiation of $E<m$ massive particles in the tunneling formalism

We use the tunneling formalism to calculate the Hawking radiation of massive particles. For $E \geq m$, we recover the traditional result, identical to the massless case. But $E<m$ particles can also tunnel across the horizon in a Hawking process. We study the probability for detecting such $E<m$ particles as a function of the distance from the horizon and the energy of the particle in the tunneling formalism. We derive a general formula and obtain simple approximations in the near-horizon limit and in the limit of large radii.