The leading eikonal operator in string-brane scattering at high energy

Understand

In this paper we present two (a priori independent) derivations of the eikonal operator in string-brane scattering.

• The first one is obtained by summing surfaces with any number of boundaries, while in the second one the eikonal operator is derived from the three-string vertex in a suitable light-cone gauge.
• This second derivation shows that the bosonic oscillators present in the leading eikonal operator are to be identified with the string bosonic oscillators in a suitable light-cone gauge, while the first one shows that it exponentiates recovering unitarity.
• This paper is a review of results obtained in two previous publications of the same authors.