2021/03/23 by Maedan, Shinji
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2103.12275
Introducing a vacuum angle θh in a strongly interacting hidden sector like QCD, we study how θh affects physical quantities in a scale invariant extension of the standard model with that hidden sector. In this model the dynamical chiral symmetry breaking occurs in the hidden sector and generates a scale \vert ⟨ q q ⟩ \vert which triggers electroweak symmetry breaking. We find that the expression for a vacuum expectation value of the Higgs field depends on θh, while the condition which determines the Higgs particle mass does not. This model contains the hidden-sector pions π0 and π± which are candidates for cold dark matter, and we find the mass difference between the hidden-sector π0 and π± will not be negligible for θh ≈ π.