Probing the CP-Violation effects in the hττ coupling at the LHC

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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.

“…The previous studies of the collider measurements of the CPV in the Higgs Yukawa couplings can be found in refs. [82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99].…”

Section: A3 the Yukawa Couplings In The Cpv 2hdmmentioning

confidence: 99%

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

Chen

Teng

et al. 2020

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“…6 Similar χ 2 Imp expressions for tracks whose trajectories do not intersect with the tau flight direction (due to resolution effects) can be found in [33,34] 7 They are tuned such that the fraction of events with good reconstructed neutrinos is the largest, and they also control the relative weight of Eq. In the per-event minimization of Eq.…”

Section: Reconstruction Of the Neutrinosmentioning

confidence: 84%

“…While the spin correlation can be partially obtained with only visible decay products [31,32], the information of neutrinos is important to help improve the reconstruction of the tau spin correlation. The technique to reconstruct the neutrino momenta from tau decays developed in our previous works [33,34] is used for the low energy e − e + collisions which makes use of the full information per event including the impact parameters of charged tracks from tau decays. Because Belle-II started taking data with the full detector in 2019 [35], it is worthwhile to simulate data with the Belle-II detector, and investigate the sensitivity one can expect from it for both tau EDM and g-2 searches.…”

Section: Event Selection and Reconstruction Of Neutrinos From τ Decaymentioning

confidence: 99%

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Search for the Electric Dipole Moment and anomalous magnetic moment of the tau lepton at tau factories

Chen

2019

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Precise measurement of the Electric Dipole Moment (EDM) and anomalous magnetic moment (g-2) of particles are important tests of Beyond Standard Model (BSM) physics. It is generally believed that the tau lepton couples more strongly to BSM due to its large mass, and can be searched for at collider experiments. A new method to approximately reconstruct the neutrinos from the hadronic decays of τ − τ + pairs produced at e − e + tau factories is proposed. With all final state particle momenta available, observables based on matrix elements and sensitive to BSM are calculated. It is estimated that with 50 ab −1 of data to be delivered by the Belle-II experiment, a tau EDM search with a 1-σ level precision of |d N P τ | < 2.04 × 10 −19 e·cm, and g-2 search with |a N P τ | < 1.75 × 10 −5 (1.5% of the SM prediction), can be expected when systematics are not considered. The new precision can effectively constrain BSM models with heavy mirror neutrinos. It can also constrain models containing a light scalar with mass at O(1 GeV), which can explain the current muon g-2 anomaly as well. The method in this work offers a new opportunity to search for BSM at current and future tau factories with high precision.

“…In the future it will be important to further improve the sensitivity to a possible CPodd component of this coupling at the LHC and future colliders, and to evaluate the baryon asymmetry corresponding to the constrained amount of CP -violation. An experimental HL-LHC projection [37] and several phenomenological analyses [38][39][40][41] have already been performed in this direction. Machine Learning (ML) may also play a useful role in further scrutinizing the CP nature of the Higgs-τ interaction [42,43].…”

Section: Jhep05(2020)056mentioning

confidence: 99%

C P violation from τ , t and b dimension-6 Yukawa couplings — interplay of baryogenesis, EDM and Higgs physics

Fuchs

Losada

Nir

et al. 2020

We explore the implications of the Standard Model effective field theory (SMEFT) with dimension-six terms involving the Higgs boson and third-generation fermion fields on the rate of Higgs boson production and decay into fermions, on the electric dipole moments (EDMs) of the electron, and on the baryon asymmetry of the Universe. We study the consequences of allowing these additional terms for each flavor separately and for combinations of two flavors. We find that a complex τ Yukawa coupling can account for the observed baryon asymmetry Y obs B within current LHC and EDM bounds. A complex b (t) Yukawa coupling can account for 4% (2%) of Y obs B , whereas a combination of the two can reach 12%. Combining τ with either t or b enlarges the viable parameter space owing to cancellations in the EDM and in either Higgs production times decay or the total Higgs width, respectively. Interestingly, in such a scenario there exists a region in parameter space where the SMEFT contributions to the electron EDM cancel and collider signal strengths are precisely SM-like, while producing sufficient baryon asymmetry. Measuring CP violation in Higgs decays to τ leptons is the smoking gun for this scenario.