BRANES, ORIENTIFOLDS AND THE CREATION OF ELEMENTARY STRINGS

The potential of a configuration of two Dirichlet branes for which the number of ND-directions is eight is determined, Depending on whether one of the branes is an anti-brane or a brane, the potential vanishes or is twice as large as the dilaton-gravitational potential, This is s hown to be related to the fact that a fundamental string is created wh en two such branes cross. Special emphasis is given to the D0-D8 syste m, for which an interpretation of these results in terms of the massiv e IIA supergravity is presented. It is also shown that the branes cann ot move non-adiabatically in the transverse direction, The configurati on of a zero-brane and an orientifold 8-plane is analyzed in a similar way, and the implications for the type IA-heterotic duality and the h eterotic matrix theory are discussed. (C) 1998 Elsevier Science B.V.