The Phase Diagram of a U(1) Higgs-Yukawa Model at Finite $\lambda$
  In this paper we investigate how the phase diagram of a U(1) symmetric Higgs-Yukawa system depends on the scalar self coupling $\lambda$. The phase diagram of similar models with continuous symmetry were extensively studied in the infinite scalar self coupling $\lambda=\infty$ limit. Recent analytical and numerical calculations at zero self coupling showed qualitatively different phase diagram, raising the question of the $\lambda$ dependence of the phase diagram. Here we use analytical (large $N_f$, perturbative and mean field) approximations as well as numerical simulations to investigate the system. 
A. Hasenfratz, K. Jansen and Y. Shen