Poloidal slice of the mean electron and positron Lorentz factor. The solid white line is a slice of the 3D closed surface encompassing the whole current layer while the dotted line locates, for this slice, the current layer. The black disk at the origin (resp. the black dashed line) is the BH event horizon (resp. the ergosphere) and the green region in the equatorial plane stands for the disk. The bottom right insert shows the distributions dN/dγ of the positrons and electrons in the volume delimited by the solid white contour, compared to a power-law (dashed line).