Thermodynamic properties of massive dilaton black holes

We numerically reanalyze static and spherically symmetric black hole solutions in an Einstein-Maxwell-dilaton system with a dilaton potential. We consider two types of potentials: $m_d^2{\phi }^2$ and $m_d^2{S}^2(S-{1)}^2{e}^{S-1}/4\mathrm{}$ where $S≔e^{-2\phi },$ which is proposed based on gluino condensation. We investigate thermodynamic properties in both cases and find that the black hole becomes an extreme solution for a finite horizon radius when a dilaton potential does not vanish. As a result, the Hawking temperature approaches zero in the extreme limit whereas it approaches a finite nonzero value in this limit for the massless dilaton case. This implies that a small amount of the dilaton mass changes the final fate of the black hole.