Constant threshold correction to electrically charged dilatonic black holes

We investigate the effect of a constant threshold correction to a general non-extreme, static, spherically symmetric, electrically charged black hole solution of the dilatonic Einstein-Maxwell Lagrangian, with an arbitrary coupling $\beta$ between the electromagnetic tensor and the dilaton field. For a small $\beta$, an exact analytical solution is obtained. For an arbitrary $\beta$, a close form solution, up to first order in the threshold correction, of the metric and the dilaton are presented. In the extremal limit, the close form solution is reduced to an exact analytical form.