Topological Nambu monopole in two Higgs doublet models

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 $$ \mathcal{O} $$ O (106) GeV3, 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 αc, 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.

Section: Conclusion and Discussionmentioning

confidence: 99%

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

Chen

Teng

et al. 2020

“…We studied the Nambu monopole in the 2HDM under both the U(1) a and (Z 2 ) C conditions in our previous study [51]. In this paper, we relax the latter and study the Nambu monopoles in more realistic cases.…”

Section: Jhep07(2020)004mentioning

confidence: 99%

“…The static stable monopole was obtained under the restriction (Z 2 ) C symmetry in ref. [51]. In contrast, here, we will investigate the Nambu monopoles without the (Z 2 ) C symmetry.…”

Section: Nambu Monopolesmentioning

confidence: 99%

“…In the previous paper [51], the present authors studied the Nambu monopole in the 2HDM, which is a magnetic monopole attached by two topological Z strings from two opposite sides. The monopole is topologically stable and a regular solution of the equation of motion (EOM) when the Higgs potential has two global symmetries; one is a global U(1) symmetry that ensures the stability of the topological Z strings.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamics of Nambu monopole in two Higgs doublet models. Cosmological Monopole Collider

Eto

Hamada

Kurachi

et al. 2020

Self Cite

We study the dynamics of the Nambu monopole in two Higgs doublet models, which is a magnetic monopole attached by two topological Z strings (Z flux tubes) from two opposite sides. The monopole is a topologically stable solution of the equation of motions when the Higgs potential has global U (1) and ℤ2 symmetries. In this paper, we consider more general cases without the ℤ2 symmetry, and find that it is no longer a static solution but moves along the Z string being pulled by the heavier string. After analytically constructing an asymptotic form of the monopole, we confirm such a motion using the numerical relaxation method. In addition, we analyze the real time dynamics of the monopole based on a point-like approximation. Consequently, if there were long string networks with the monopoles in the early universe, the monopole accelerates nearly to the speed of light emitting electromagnetic radiations as a synchrotron accelerator, and collides to an anti-monopole on the string. This collision event, which we call the cosmological monopole collider, can produce much heavier particles than those we can see today, e.g., at the Large Hadron Collider.

“…The electroweak string is a string containing flux tubes of the SU(2) W × U(1) Y gauge fields like the Abrikosov-Nielsen-Olesen vortex [41,42] and has been studied in the SM [43][44][45][46][47][48][49][50][51] (see ref. [52] for review), and in two Higgs doublet models (2HDM) [53][54][55][56][57][58][59][60][61][62] (for recent comprehensive studies, see refs. [63,64]).…”

Section: Introductionmentioning

confidence: 99%

Electroweak axion string and superconductivity

Abe

Hamada

Yoshioka

2021

Self Cite

We study the axion strings with the electroweak gauge flux in the DFSZ axion model and show that these strings, called the electroweak axion strings, can exhibit superconductivity without fermionic zeromodes. We construct three types of electroweak axion string solutions. Among them, the string with W-flux can be lightest in some parameter space, which leads to a stable superconducting cosmic string. We also show that a large electric current can flow along the string due to the Peccei-Quinn scale much higher than the electroweak scale. This large current induces a net attractive force between the axion strings with the same topological charge, which opens a novel possibility that the axion strings form Y-junctions in the early universe.