Closed-String Tachyon Condensation and the Worldsheet Super-Higgs Effect

Abstract

Alternative gauge choices for worldsheet supersymmetry can elucidate dynamical phenomena obscured in the usual superconformal gauge. In the particular example of the tachyonic $E_8$ heterotic string, we use a judicious gauge choice to show that the process of closed-string tachyon condensation can be understood in terms of a worldsheet super-Higgs effect. The worldsheet gravitino assimilates the goldstino and becomes a dynamical propagating field. Conformal, but not superconformal, invariance is maintained throughout.Comment: 4 pages; v2: typos corrected, a reference added; v3: final version, to appear in Phys. Rev. Lett. (abstract and intro modified for a broader audience