Collapsing domain walls in the two-Higgs-doublet model and deep insights from the EDM

Abstract

We study the domain wall solutions in the general two-Higgs-doublet model (2HDM) with a CP-violating phase. The 2HDM with the spontaneouse CP violation is found to have domain wall solutions whose tensions are O(10 6 ) GeV 3 , which are excluded by the Zel'dovich-Kobzarev-Okun bound. With the explicit CP-violating (CPV) terms as the so-called biased term in the scalar potential, domain walls can collapse in the early Universe. The sizes of the explicit CP violation can be constrained from the Big Bang nucleosynthesis. This constraint is converted to the CPV mixing of α c , and is mostly sensitive to the mass splittings between two heavy neutral Higgs bosons. We estimate the possible gravitational wave signals and the electric dipole moment (EDM) predictions due to the domain wall collapsing. It turns out that the peak spectrum of the GW from the domain wall collapsing cannot be probed in any future program. In contrast, the untenable regions with very tiny explicit CPV parameter in the Higgs potential has been partially excluded by the latest electron EDM measurements at the ACME-II and will be further confirmed or excluded by the future ACME-III projection.

Electron EDM in the complex two-Higgs doublet model

“…[13] to rectify the shortcomings of the earlier analyses to obtain a gauge-invariant result. Even though this work still does not constitute a complete calculation of the electron EDM as emphasized by the authors, their results have become a standard reference for subsequent phenomenological studies involving the electron EDM in the C2HDM [21][22][23][24][25] (see also [26][27][28][29][30][31][32][33][34] for recent related studies). Therefore in this section, we compare our results with Abe et.…”

Topological structure of Nambu monopole in Two Higgs doublet models -- Fiber bundle, Dirac's quantization and dyon --

“…Note that, in Eq. (V. 46), there is also a contribution from the Z flux confined inside the two Z strings (the second term), in addition to that from the electromagnetic gauge field (the first term). Using the definitions of the gauge fields in Eqs.…”

“…[28][29][30][31][32] and references therein. One of the most remarkable aspects of 2HDM distinguishable from the SM may be that it has a much richer vacuum structure than the SM, thereby allowing a variety of topologically stable solitons, in addition to non-topological solitons [33][34][35][36][37][38][39][40][41] analogous to the SM; domain walls [42][43][44][45][46][47], membranes [48,49], and cosmic strings such as topological Z strings [44,45,50,51] (see also Ref. [52]).…”

CP violating effects in $^{210}$Fr and prospects for new physics beyond the Standard Model

“…The leading contribution arises instead, at the two-loop level with heavy fermion loops, often called Barr-Zee type diagrams (see Fig. 1) [26][27][28][29][30][31][32][33], whose leading contribution is . Here Y f and Y P f are the scalar and pseudoscalar couplings of the Yukawa interaction between the fermion f and the lightest Higgs boson H, respectively.…”