Stable D8-branes and Tachyon Condensation in Type 0 Open String Theory

Abstract

We consider non-BPS D8 (and D7) branes in type 0 open string theory and describe under which circumstances these branes are stable. We find stable non-BPS D7 and D8 in type 0 with and without D9-branes in the background. By extending the descent relations between D-branes to type 0 theories, the non-BPS D8-brane is considered as the result of a tachyon condensation of a D9 anti-D9 pair in type 0. We study the condensation of the open string tachyons in type 0 with generic gauge groups giving rise to different configurations involving non-BPS D8-branes and discuss the stability in each case. The results agree with the topological analysis of the vacuum manifold of the tachyon potential for each case.