Conformal Complex Singlet Extension of the Standard Model: Scenario for Dark Matter and a Second Higgs Boson

Understand

We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction.

• The global $U(1)$ symmetry of the complex singlet can be either broken or unbroken and we study each scenario.
• In the unbroken case, the global $U(1)$ symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance.
• In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model's couplings and masses.