Tachyon condensation using the disc partition function

TL;DR

This paper investigates tachyon condensation in the D0-D2 system using the disc partition function approach within open superstring field theory, confirming the expected mass defect in a large B-field limit.

Contribution

It applies the disc partition function method to analyze tachyon condensation in a D0-D2 system with a large B-field, providing a perturbative calculation that matches expected results.

Findings

Mass defect for D0-D2 bound state matches theoretical predictions.

Perturbation theory is valid due to near-marginal boundary operators.

Large B-field simplifies the analysis of tachyon condensation.

Abstract

It has been recently proposed that the background independent open superstring field theory action is given by the disc partition function with all possible open string operators inserted at the boundary of the disc. We use this proposal to study tachyon condensation in the D0-D2 system. We evaluate the disc partition function for the D0-D2 system in presence of a large Neveu-Schwarz B-field using perturbation theory. This perturbative expansion of the disc partition function makes sense as the boundary tachyon operator for the large Neveu-Schwarz B-field is almost marginal. We find that the mass defect for the formation of the D0-D2 bound state agrees exactly with the expected result in the large B-field limit.