The oneloop fivegraviton scattering amplitude and its lowenergy limit
Abstract
A covariant pathintegral calculation of the evenspin structure contribution to the oneloop Ngraviton scattering amplitude in the typeII superstring theory is presented. The apparent divergence of the N = 5 amplitude is resolved by separating it into twelve independent terms corresponding to different orders of inserting the graviton vertex operators. Each term is well defined in an appropriate kinematic region and can be analytically continued to physical regions where it develops branch cuts required by unitarity. The zeroslope limit of the N = 5 amplitude is performed, and the Feynman diagram content of the lowenergy field theory is examined. Both oneparticle irreducible (1PI) and oneparticle reducible (1PR) graphs with massless internal states are generated in this limit. One set of 1PI graphs has the same divergent dependence on the cutoff as that found in the fourgraviton case, and it is proved that such graphs exist for all N. The 1PR graphs are contributed by the poles in the worldsheet chiral Green functions.
 Publication:

Nuclear Physics B
 Pub Date:
 March 1993
 DOI:
 10.1016/05503213(93)90248N
 arXiv:
 arXiv:hepth/9205097
 Bibcode:
 1993NuPhB.393..337L
 Keywords:

 High Energy Physics  Theory
 EPrint:
 23 pages, ITPSB9263