D-brane chemistry

We study several different kinds of bound states built from D-branes and orientifolds. These states are to atoms what branonium - the bound state of a brane and its anti-brane - is to positronium, inasmuch as they typically involve a light brane bound to a much heavier object with conserved charges which forbid the system's decay. We find the fully relativistic motion of a probe Dp′l-brane in the presence of source Dp-branes is integrable by …