RELATIVISTIC BRANE SCATTERING

We calculate relativistic phase shifts resulting from the large impact parameter scattering of O-branes off p-branes within supergravity. Th eir full functional dependence on velocity agrees with that obtained b y identifying the p-branes with D-branes in string theory. These proce sses are also described by O-brane quantum mechanics, but only in the non-relativistic limit. We show that an improved O-brane quantum mecha nics based on a Born-Infeld-type Lagrangian also does not yield the re lativistic results. The scattering of O-branes off bound states of arb itrary numbers of O-branes and 2-branes is analyzed in detail, and we find agreement between supergravity and string theory at large distanc es to all orders in velocity. Our careful treatment of this system, wh ich embodies the 11-dimensional kinematics of 2-branes in M(atrix) the ory, makes it evident that control of 1/n corrections will be necessar y in order to understand our relativistic results within M(atrix) theo ry. (C) 1997 Elsevier Science B.V.