CPT Invariance of String Models in a Minkowski Background

Andrea Pasquinucci, Kaj Roland

Published 1996-02-06Version 1

We study the space-time CPT properties of string theories formulated in a flat Minkowski background of even dimension. We define CPT as a world-sheet transformation acting on the vertex operators and we prove the CPT invariance of the string $S$-matrix elements. Some related issues, including the connection between spin and statistics of physical string states, are also considered.