Euclidean Solutions in Broken Phase and Electro-Weak Dynamics
  A Higgs-Yukawa system in a broken phase and Euclidean solutions are investigated. Although it has been believed that there are no Euclidean solutions in the broken phase in 4-dimension, we find numerically ones in the phase due to the effect of a strong Yukawa coupling. The complex Yukawa coupling is necessary for the stability of the solution. The extension to a complex Higgs-Yukawa system is also investigated. 
Hiroyuki Kanada, Hiroto So and Shin Takeda