Loop effects on the Higgs decay widths in extended Higgs models

Kanemura, Shinya; Kikuchi, Mariko; Mawatari, Kentarou; Sakurai, Kodai; Yagyu, Kei

doi:10.1016/j.physletb.2018.06.035

“…There have been many studies in the literature on the implications of the Higgs precision measurements at current and future colliders on the 2HDMs [39][40][41][42][43][44][45][46][47]. In recent works [48][49][50][51][52][53], we examined the achievable sensitivity of the Higgs and Z factories to probe the virtual effects of the two Higgs doublet model (2HDM) of Type-II and Type-I.…”

Section: Jhep01(2021)045mentioning

confidence: 99%

Comparative studies of 2HDMs under the Higgs boson precision measurements

Han

¹

,

Li

²

,

Su

³

et al. 2021

J. High Energ. Phys.

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We perform comparative studies for four types of the two Higgs Doublet Models (2HDMs) under the precision measurements of the Standard Model (SM) Higgs observables at the proposed Higgs factories. We explore the discovery potential based on the hypothetical deviations in the precision data for the 2HDMs up to one-loop level. We find 5σ observability from the χ2 fitting in a significant theory parameter space at future Higgs factories. For the Type-I 2HDM, regions with cos(β − α) ≲ −0.1 or cos(β − α) ≳ 0.08 are discoverable at more than 5σ level. For the other three types of 2HDMs, the 5σ region is even bigger: | cos(β − α)| ≳ 0.02 for tan β ∼ 1. At small and large values of tan β, the region in cos(β − α) is further tightened. We examine the extent to which the different 2HDM theories may be distinguishable from one to the other at the 95% Confidence Level with four benchmark points as case studies. We show that a large part of the parameter space of the other types of 2HDMs can be distinguished from the benchmark points of the target model. The impacts of loop corrections are found to be significant in certain parameter regions.

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“…Finally, we would like to mention about the difference of our results and previous works. Discriminations of extended Higgs models through the precise measurement of the SM-like Higgs boson couplings have been studied at tree level [55] and the one-loop level [81,82]. In these works, the masses of the additional Higgs bosons, M and the mixing angles are considered to be free parameters, and they are scanned under the theoretical and experimental constraints.…”

Section: Jhep02(2021)046mentioning

confidence: 99%

New scenario for aligned Higgs couplings originated from the twisted custodial symmetry at high energies

Aiko

¹

,

Kanemura

²

2021

J. High Energ. Phys.

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We investigate a new scenario of the two Higgs doublet model, where the current experimental data for the electroweak rho parameter and those for the Higgs boson couplings can be simultaneously explained. In this scenario, the two Higgs doublet model is supposed to be a low energy effective theory up to a high energy scale Λ, above which a fundamental theory should appear. It is assumed that the Higgs potential respects a global symmetry at Λ (the twisted custodial symmetry), which is to be given as a consequence of the global symmetry structure of the fundamental theory above Λ. By the analysis using one-loop renormalization group equations, the above experimental data can be explained in a natural way even when the masses of the extra Higgs bosons are near the electroweak scale. We also discuss the predictions on the mass spectrum of the additional Higgs bosons and also those on the coupling constants of the standard-model-like Higgs boson, which make it possible to test this scenario at the current and future collider experiments.

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“…In order to see differences in the prediction among these models, it is quite important to calculate the renormalized SM-like Higgs boson vertices in a consistent and systematic way. The H-COUP program [52,53] enables us to evaluate the decay rates including higher-order corrections for the SM-like Higgs boson in the HSM, the IDM and the 2HDM with four types of Yukawa interactions classified under the softly-broken Z 2 symmetry [54,55]. Also, other numerical tools to evaluate the decay of the Higgs boson with radiative corrections are available; e.g., 2HDECAY [56] and Prophecy4f [57].…”

Section: (): V-volmentioning

confidence: 99%

Next-to-leading-order corrections to the Higgs strahlung process from electron–positron collisions in extended Higgs models

Aiko

¹

,

Kanemura

²

,

Mawatari

³

2021

Self Cite

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We present the cross section for $$e^{+}e^{-}\rightarrow hZ$$ e + e - → h Z with arbitrary sets of electron and Z boson polarizations at the full next-to-leading order in various extended Higgs models, such as the Higgs singlet model (HSM), the inert doublet model (IDM) and the two Higgs doublet model (2HDM). We systematically perform complete one-loop calculations to the helicity amplitudes in the on-shell renormalization scheme, and present the full analytic results as well as numerical evaluations. The deviation $$\Delta R^{hZ}$$ Δ R hZ in the total cross section from its standard model (SM) prediction is comprehensively analyzed, and the differences among these models are discussed in details. We find that new physics effects appearing in the renormalized hZZ vertex almost govern the behavior of $$\Delta R^{hZ}$$ Δ R hZ , and it takes a negative value in most cases. The possible size of $$\Delta R^{hZ}$$ Δ R hZ reaches several percent under the theoretical and experimental bounds. We also analyze the deviation $$\Delta R^{hZ}_{XY}$$ Δ R XY hZ in the total cross section times decay branching ratios of the discovered Higgs boson by utilizing the program. It is found that the four types of 2HDMs can be discriminated by analyzing the correlation between $$\Delta R^{hZ}_{\tau \tau }$$ Δ R τ τ hZ and $$\Delta R^{hZ}_{bb}$$ Δ R bb hZ and those between $$\Delta R^{hZ}_{\tau \tau }$$ Δ R τ τ hZ and $$\Delta R^{hZ}_{cc}$$ Δ R cc hZ . Furthermore, the HSM and the IDM can be discriminated from the 2HDMs by measuring $$\Delta R^{hZ}_{WW}$$ Δ R WW hZ . These signatures can be tested by precision measurements at future Higgs factories such as the International Linear Collider.

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Loop effects on the Higgs decay widths in extended Higgs models

Cited by 39 publications

References 83 publications

Comparative studies of 2HDMs under the Higgs boson precision measurements

Comparative studies of 2HDMs under the Higgs boson precision measurements

New scenario for aligned Higgs couplings originated from the twisted custodial symmetry at high energies

Next-to-leading-order corrections to the Higgs strahlung process from electron–positron collisions in extended Higgs models

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