Abstract
The dressed ladder Schwinger-Dyson equation for the fermion self-energy with an additional four-fermion coupling term is studied both analytically and numerically. We limit our analysis to asymptotically free theories with a large hierarchy between the confinement scale and the ultraviolet cutoff . The dependence of the dynamical mass and the fermion condensate on the four-fermion coupling strength is derived. It is found that there exists a critical four-fermion coupling strength , such that in the region the dynamical mass is of the order of the confinement scale , while in the region the dynamical mass is of the order of the cutoff . In the region , the condensate picks up an enhancement factor , and in the limit , reaches the order of . In the region , the condensate is of the order of . The application of the equation to technicolor theories is also discussed.
- Received 24 May 1989
DOI:https://doi.org/10.1103/PhysRevD.40.2697
©1989 American Physical Society