A stable non-BPS configuration from intersecting branes and antibranes

We describe a tachyon-free stable non-BPS brane configuration in type-IIA s tring theory. The configuration is an elliptic model involving rotated NS5- branes, D4-branes and anti-D4 branes, and is dual to a fractional brane-ant ibrane pair placed at a conifold singularity. This configuration exhibits a n interesting behaviour as we vary the radius of the compact direction. Bel ow a critical radius the D4 and anti-D4 branes are aligned, but as the radi us increases above the critical value the potential between them develops a minimum away from zero. This signals a phase transition to a configuration with finitely separated branes.