Two-loop corrections to the Higgs trilinear coupling in models with extended scalar sectors

Braathen, Johannes; Kanemura, Shinya

doi:10.22323/1.390.0051

“…The triple Higgs coupling λ hhh can deviate from the SM value λ SM hhh = m 2 h 2v in many new physics models [21][22][23][24][25][26][27][28][29][30]. Here, m T , θ L , κ t , κ t , y T , y T are all real parameters, while y tT L , y tT R can be complex.…”

Section: Ii2 Simplified Modelmentioning

confidence: 99%

Higgs boson to γZ decay as a probe of flavor-changing neutral Yukawa couplings

He

¹

2020

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With the deeper study of Higgs particle, Higgs precision measurements can be served to probe new physics indirectly. In many new physics models, vectorlike quarks T L , T R occur naturally. It is important to probe their couplings with standard model particles. In this work, we consider the singlet T L , T R extended models and show how to constrain the Tth couplings through the h → γZ decay at high-luminosity LHC. First, we derive the perturbative unitarity bounds on jy tT L;R j with other couplings set to be zeros simply. To optimize the situation, we take m T ¼ 400 GeV and s L ¼ 0.2 considering the experimental constraints. Under this benchmark point, we find that the future bounds from h → γZ decay can limit the real parts of y tT L;R in the positive direction to be O(1) because of the double enhancement. For the real parts of y tT L;R in the negative direction, it is always surpassed by the perturbative unitarity. Moreover, we find that the top quark electric dipole moment can give stronger bounds (especially the imaginary parts of y tT L;R) than the perturbative unitarity and h → γZ decay in the off-axis regions for some scenarios.

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“…The majority of these analyses were performed at leading order. A few exceptions where one-loop effects are considered include i) the computation of the tri-linear self coupling of the SM-like Higgs boson [8][9][10], ii) one-loop corrections to the Higgs effective potential [3], the running of the Higgs/scalar masses and the running of the scalar parameters [5] (see also [11]), iii) one-loop induced cross-sections relevant for direct detection [12] and iv) induced one-loop effects for photon production: Higgs decay to a photon pair [13] and DM annihilation to photons [14]. Yet, the relic density of DM as extracted by PLANCK [15] is a precision measurement at the percent level that calls for an equally precise theoretical prediction.…”

Section: Introductionmentioning

confidence: 99%

Relic density of dark matter in the inert doublet model beyond leading order: The heavy mass case

Banerjee

¹

,

Boudjema

²

,

Chakrabarty

³

et al. 2019

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A full renormalisation of the Inert Doublet Model (IDM) is presented and exploited for a precise calculation of the relic density of Dark Matter (DM) at one-loop. In this first paper, we study the case of a DM candidate with m DM ∼ 500 GeV. In this regime, the co-annihilation channels are important. We therefore compute, for a wide range of relative velocities, the full Next-to-Leading-Order (NLO) electroweak corrections to 7 annihilation/co-annihilation processes that contribute ∼ 70% to the relic density of DM. These corrected cross-sections are interfaced with micrOMEGAs to obtain the one-loop correction to the freeze-out relic density. Due to the accurate measurement of this observable, the one-loop corrections are relevant. We discuss the one-loop renormalisation scheme dependence and point out the influence, at one-loop, of a parameter that solely describes the scattering in the dark sector. A tree-level computation of the relic density is not sensitive to this parameter.

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“…Therefore the higher-order effects should be studied carefully. For example, in Refs [129,130],. two-loop effects for the Higgs trilinear coupling λ hhh are estimated in various extended Higgs models.…”

mentioning

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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Two-loop corrections to the Higgs trilinear coupling in models with extended scalar sectors

Cited by 3 publications

References 34 publications

Higgs boson to γZ decay as a probe of flavor-changing neutral Yukawa couplings

Higgs boson to γZ decay as a probe of flavor-changing neutral Yukawa couplings

Relic density of dark matter in the inert doublet model beyond leading order: The heavy mass case

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

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