The Heterotic Life of the D-particle

TL;DR

This paper explores the dynamics of D-particles in type I' string theory and their dual heterotic states, deriving a quantum mechanical model, analyzing bound states, and confirming results with supergravity predictions.

Contribution

It introduces a quantum mechanical system for D-particles in type I' string theory that accounts for orientifolds and D8-branes, and compares scattering results with supergravity.

Findings

Bound states are consistent with dual heterotic descriptions.

Phase shifts in scattering match supergravity expectations.

Cancellation effects observed in transverse motion.

Abstract

We study the dynamics of D-particles (D0-branes) in type I' string theory and of the corresponding states in the dual heterotic description. We account for the presence of the two 8-orientifolds (8 dimensional orientifold planes) and sixteen D8-branes by deriving the appropriate quantum mechanical system. We recover the familiar condition of eight D8-branes for each 8-orientifold. We investigate bound states and compute the phase shifts for the scattering of such states and find that they agree with the expectations from the supergravity action. In the type I' regime we study the motion transverse to the 8-orientifold and find an interesting cancellation effect.