High-energy behavior of phi3 theory in six dimensions

We examine the high-energy behavior of scattering amplitudes in an asymptotically free field theory, phi3 theory in six dimensions. It is seen that, as in non-Abelian gauge theories, the lack of transverse-momentum cutoff gives rise to a ln2s expansion. Within this leading-logarithm approximation, ladder diagrams dominate in each order and their series corresponds to a fixed Regge cut. The nonleading logarithmic corrections and a (truss) bridge between our results and those for phi4 in four dimensions are discussed as is the possible change in the Regge singularity if a different order of summation is followed