D-brane form factors at high energy

TL;DR

This paper analyzes the high-energy behavior of D-brane form factors in string theory, revealing how their effective size scales with energy and perturbation order, with special behavior for D-instantons.

Contribution

It provides a comprehensive all-orders analysis of D-brane form factors at high energies using saddle point techniques, highlighting size scaling and special cases like D-instantons.

Findings

D-brane effective size grows linearly with energy at high orders

D-instanton form factors remain point-like at high energies

Qualitative features are independent of probe state character

Abstract

We study the high energy, fixed angle, asymptotics of D-brane form factors to all orders in string perturbation theory, using the Gross-Mende saddle point techniques. The effective interaction size of all D-branes grows linearly with the energy as (alpha') E/n, where n is the order of perturbation theory, except for the D-instanton, whose form factor is dominated by end-point contributions, and remains point-like at high orders. The qualitative features are independent of the R-R or NS-NS character of the states used to probe the D-brane.