Cornering Spontaneous CP Violation with Charged-Higgs Searches

Understand

Decades of precision measurements have firmly established the Kobayashi-Maskawa phase as the dominant source of the CP violation observed in weak quark decays.

• However, it is still unclear whether CP violation is explicitly encoded in complex Yukawa matrices or instead stems from spontaneous symmetry breaking with underlying CP-conserving Yukawa and Higgs sectors.
• Here we study the latter possibility for the case of a generic two-Higgs-doublet model.
• We find that theoretical constraints limit the ratio $t_\beta$ of the vacuum expectation values to the range $0.22 \leq t_\beta \leq 4.5$ and imply the upper bounds $M_{H^\pm}\leq 435$ GeV, $M_{H_{2}^0} \leq 485$ GeV and $M_{H_{3}^0} \leq 545$ GeV for the charged and extra neutral Higgs masses.