Ramond-Ramond bosons in superstring theory

Abstract

We discuss the nature of the degenerate bispinor vacuum states in the Ramond‐Ramond sectors of four‐dimensional models based on the superstring. A covariant separation of the spin content into vector bosons and scalar particles is given, and an orthonormal basis for the space of states is defined. Because of the physical state conditions, the bi‐spinors are given as solutions to the Dirac‐Ramond equations in the covariant gauge. The conformal fields corresponding to the emission of these states are computed as holomorphic times antiholomorphic fermion emission operators. The on‐shell three point amplitudes involving these massless particles are derived, and their role in superstring phenomenology is described.