The Tachyon Potential in Witten's Superstring Field Theory

Abstract

We study the tachyon potential in the NS sector of Witten's cubic superstring field theory. In this theory, the pure tachyon contribution to the potential has no minimum. We find that this remains the case when higher modes up to level two are included.Comment: Latex, 10 pages, 1 figure, published version, comments added regarding the absence of the twist-invariance and the singular behaviour of the potentia