SCATTERING AMPLITUDES AND THE CPT THEOREM IN STRING THEORY
A. PASQUINUCCI, K. ROLAND · 1997
We discuss the role of the CPT transformation in first quantized string theories, both on the world-sheet and in the space-time. We explicitly show that the space-time CPT theorem holds for all first-quantized (perturbative) string theories in a Minkowski background of even dimension $D>2$.