Generating a mass gap using Feynman diagrams in an asymptotically free theory

Using the example of a two dimensional four-fermion lattice field theory, we show that Feynman diagrams can generate a mass gap in a theory with massless fermions that interact via a marginally relevant coupling. We show this by introducing an infrared cutoff that makes the perturbation series for the partition function convergent. We use a Monte Carlo approach to sample sufficiently high orders of diagrams and thus expose the presence of the mass gap.

Duke Scholars

Author Shailesh Chandrasekharan Physics