Probing 4-Dimensional Nonsupersymmetric Black Holes Carrying D0- and D6-brane charges

We discuss a 4-dimensional nonsupersymmetric black hole solution to low energy type IIA string theory which carries D0- and D6-brane charges. For equal charges this solution reduces to the one discussed recently by Sheinblatt. We present a new parametrization of the solution in terms of four numbers which reveals the underlying brane and antibrane structure of the black hole arbitrarily far from extremality. In this parametrization, the entropy of the general nonextremal black hole takes on a simple U-duality invariant form. A Yang-Mills solution for the brane configuration corresponding to the extremal case is constructed and a computation of the 1-loop matrix theory potential for the scattering of a 0-brane probe off this brane configuration done. We find that this agrees with the 1-loop potential obtained from a supergravity calculation in the limit in which the ratio of the 0-brane to 6-brane charges is large.