Pomeron factorization in general dual models

A microscopic description of absorption in high-energy string-brane collisions

“…They are enhanced by an additional power of n when the open and the closed indices coincide 16) where the last approximation holds since k n. This feature will lead to a simple formula for the absorption of a generic closed string state. Finally the coefficients linear in the string modes behave as follows:…”

“…The closed-open vertex for the bosonic string for the case of purely Neumann boundary conditions was first discussed in [15,16] and then generalized to include ghosts [18] and purely Dirichlet boundary conditions [19]. The extension to the superstring in the Green-Schwarz formalism was considered in [17].…”

“…We then expand the exponential rewriting the operator in eq. (5.12) as follows: 16) where the operator W is given by…”

“…As the energy increases we are therefore exploring higher and higher levels of the spectrum. Since the covariant methods are not very suitable to deal with generic excited states, we will work in the light-cone gauge and derive the form of the open state by taking the high-energy limit of the light-cone closed-open vertex [15][16][17][18][19].…”

“…Since the covariant methods are not very suitable to study highly excited string states, we then introduce the light-cone closed-open vertex [15][16][17][18][19] that encodes all the correlation functions between arbitrary closed and open string states. This vertex can be derived by a variety of methods: factorizing the non-planar one-loop two open-string amplitude [15,16], finding the operator solution to the continuity conditions for the string coordinates [17,19] or evaluating the string path integral [18]. It can also be derived using the DDF operators, following the analysis in [31] for the three openstring vertex.…”