Covariant Superstring Fermionic Amplitudes. Vertex Operators And Picture Changing

G. ALDAZABAL; M. BONINI; C. NUÑEZ

NUCLEAR PHYSICS B

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 1989

0550-3213

Massive Ramond and Neveu-Schwarz vertex operators in the  ghost representations respectively are obtained from the factorization of the scattering amplitude of an arbitrary number of bosonic and fermionic massless states on general Riemann surfaces. The correlators for the ghost field of charge -1 and its derivatives are given as well as the normal ordering prescriptions to be used in computing scattering amplitudes. The vertex operators for the massless and the first two excited levels, both of the Ramond and the Neveu-Schwarz sector are given explicitly. The picture changing mechanism is considered and applied to relate the Neveu-Schwarz vertices in different representations.