Dynamical generation of fermion mass in a scalar-fermion theory with $λφ^4$ interaction
Somnath Majumder, Krishnendu Mukherjee
Abstract
The effective potential for a scalar theory with $λφ^4$ interaction, coupled to a massless fermion through Yukawa interaction is calculated by summing over infinite number of two particle irreducible (2PI) diagrams of two different types and a 2PI diagram of a third type using Cornwall, Jackiw and Tomboulis (CJT) method. There is an inversion symmetry present in the effective potential under $φ\rightarrow -φ$. At large coupling it exhibits minima below the zero potential line and on either side of the maximum at $φ=0$. The fermion acquires a mass at any non-trivial, positive minimum breaking the inversion symmetry of the vacuum.
