BPS Bound States Of D0-D6 And D0-D8 Systems In A B-Field

TL;DR

This paper explores how turning on a B-field induces supersymmetry and BPS bound states in D0-D6 and D0-D8 brane systems, revealing moduli-dependent state jumps and connections to noncommutative Yang-Mills theory.

Contribution

It demonstrates the existence of BPS bound states in D0-D6 and D0-D8 systems with B-fields and analyzes their properties across different supersymmetric loci.

Findings

BPS bound states exist in D0-D6 and D0-D8 systems with B-fields.

Number of 1/8 BPS states jumps with moduli changes.

Noncommutative Yang-Mills describes these systems at infinite B-field limit.

Abstract

The D0-D6 system, which is not supersymmetric in the absence of a Neveu-Schwarz B-field, becomes supersymmetric if a suitable constant B-field is turned on. On one side of the supersymmetric locus, this system has a BPS bound state, and on the other side it does not. After compactification on T^6, this gives a simple example in which the number of 1/8 BPS states jumps as the moduli of the compactification are changed. The D0-D8 system in a B-field has two different supersymmetric loci, only one of which is continuously connected to the familiar supersymmetric D0-D8 system without a B-field. In a certain range, the D0-D8 system also has a BPS bound state. In the limit in which the B-field goes to infinity, supersymmetric D0-D6 and D0-D8 systems and their bound states can be studied using noncommutative Yang-Mills theory.