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

TL;DR

This paper investigates how high-energy closed strings are absorbed by Dp-branes during collisions at microscopic scales, revealing the transition from elastic scattering to absorption and open string excitation.

Contribution

It provides a perturbative analysis of absorption phenomena in high-energy string-brane collisions at sub-string-scale impact parameters, focusing on the disk level description.

Findings

Absorption becomes significant at small impact parameters.

The closed string transforms into a heavy open string upon absorption.

The study offers a simplified disk-level model for the process.

Abstract

We study the collision of a highly energetic light closed string off a stack of Dp-branes at (sub)string-scale impact parameters and in a regime justifying a perturbative treatment. Unlike at larger impact parameters - where elastic scattering and/or tidal excitations dominate - here absorption of the closed string by the brane system, with the associated excitation of open strings living on it, becomes important. As a first step, we study this phenomenon at the disk level, in which the energetic closed string turns into a single heavy open string at rest whose particularly simple properties are described.