D0-brane recoil revisited

TL;DR

This paper revisits D0-brane recoil in string scattering, demonstrating that the worldline formalism naturally cancels infrared divergences and introduces a novel bilocal recoil operator that reproduces the amplitudes.

Contribution

It presents a systematic worldline formalism for D0-brane recoil that automatically cancels divergences and proposes a new bilocal recoil operator for the conformal field theory.

Findings

Infrared divergences are canceled in the worldline formalism.

A new bilocal recoil operator reproduces the scattering amplitudes.

The approach offers a systematic way to incorporate recoil effects.

Abstract

One-loop string scattering amplitudes computed using the standard D0-brane conformal field theory (CFT) suffer from infrared divergences associated with recoil. A systematic framework to take recoil into account is the worldline formalism, where fixed boundary conditions are replaced by dynamical D0-brane worldlines. We show that, in the worldline formalism, the divergences that plague the CFT are automatically cancelled in a non-trivial way. The amplitudes derived in the worldline formalism can be reproduced by deforming the CFT with a specific "recoil operator", which is bilocal and different from the ones previously suggested in the literature.