Automatic predictions in the Georgi-Machacek model at next-to-leading order accuracy

Degrande, Céline; Hartling, Katy; Logan, Heather E.; Peterson, A.; Zaro, Marco

doi:10.1103/physrevd.93.035004

Cited by 40 publications

(38 citation statements)

References 173 publications

(178 reference statements)

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“…For the necessary production channels we have used a modified version of the Madgraph [69] framework developed for the GM model in [70] to compute cross sections at leading order for an 8 and 13 TeV LHC. There are O(1) largely model independent k-factors [25,71] arising from corrections which are neglected, but this will not qualitatively change our results and can easily be included in a more precise analysis.…”

Section: Lhc Diphoton Limits and 95 Gev Excessmentioning

confidence: 99%

Light (and darkness) from a light hidden Higgs

Vega

Vega-Morales

Xie

2018

J. High Energ. Phys.

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We examine light diphoton signals from extended Higgs sectors possessing (approximate) fermiophobia with Standard Model (SM) fermions as well as custodial symmetry. This class of Higgs sectors can be realized in various beyond the SM scenarios and is able to evade many experimental limits, even at light masses, which are otherwise strongly constraining. Below the W W threshold, the most robust probes of the neutral component are di and multi-photon searches. Utilizing the dominant Drell-Yan Higgs pair production mechanism and combining it with updated LHC diphoton data, we derive robust upper bounds on the allowed branching ratio for masses between 45 − 160 GeV. Furthermore, masses 110 GeV are ruled out if the coupling to photons is dominated by W boson loops. We then examine two simple ways to evade these bounds via cancellations between different loop contributions or by introducing decays into an invisible sector. This also opens up the possibility of future LHC diphoton signals from a light hidden Higgs sector. As explicit realizations, we consider the Georgi-Machacek (GM) and Supersymmetric GM (SGM) models which contain custodial (degenerate) Higgs bosons with suppressed couplings to SM fermions and, in the SGM model, a (neutralino) LSP. We also breifly examine the recent ∼ 3σ CMS diphoton excess at ∼ 95 GeV.

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Section: Lhc Diphoton Limits and 95 Gev Excessmentioning

confidence: 99%

Light (and darkness) from a light hidden Higgs

Vega

Vega-Morales

Xie

2018

J. High Energ. Phys.

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“…This extended scalar sector reveals parallels with the so-called Georgi-Machacek model [26][27][28] (for recent phenomenological investigations see also [29][30][31][32][33]), which also predicts the appearance of a real as well as a complex SU(2) L triplet in the scalar sector. Whether or not these extra states contribute to the breaking of electroweak symmetry, as in the Georgi-Machacek model, is an interesting open question to be addressed in future research (see e.g.…”

Section: Jhep08(2017)142mentioning

confidence: 95%

A UV complete compositeness scenario: LHC constraints meet the lattice

Debbio

Englert

Zwicky

2017

J. High Energ. Phys.

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We investigate a recently proposed UV-complete composite Higgs scenario in the light of the first LHC runs. The model is based on a SU(4) gauge group with global flavour symmetry breaking SU(5) → SO(5), giving rise to pseudo Nambu-Goldstone bosons in addition to the Higgs doublet. This includes a real and a complex electroweak triplet with exotic electric charges. Including these, as well as constraints on other exotic states, we show that LHC measurements are not yet sensitive enough to significantly constrain the model's low energy constants. The Higgs potential is described by two parameters which are on the one hand constrained by the LHC measurement of the Higgs mass and Higgs decay channels and on the other hand can be computed from correlation functions in the UV-complete theory. Hence to exclude the model at least one constant needs to be determined and to validate the Higgs potential both constants need to be reproduced by the UV-theory. Due to its UV-formulation, a certain number of low energy constants can be computed from first principle numerical simulations of the theory formulated on a lattice, which can help in establishing the validity of this model. We assess the potential impact of lattice calculations for phenomenological studies, as a preliminary step towards Monte Carlo simulations.

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“…For the mixing angles we used two combinations of values lying inside the allowed area of the parameter space determined by the authors of Ref. [16] in their study of fiveplet states production at the LHC. We thus considered the sets of values (s H , s α ) = (0.1, 0.2) and (s H , s α ) = (0.1, −0.3), which allows us to illustrate the behavior of ∆κ γ .…”

Section: Numerical Discussionmentioning

confidence: 99%

“…All of these multiplets are mass degenerate as a result of the custodial symmetry. The phenomenology of the GMM has been broadly studied over the recent years [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. For instance, a study of the search and production of the GMM Higgs bosons at the LHC has been analyzed in [16,17], and its phenomenology at a future electron-positron collider has been reported in [18].…”

Section: Introductionmentioning

confidence: 99%

WWV ( V=γ , Z ) vertex in the Georgi-Machacek model

2016

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The CP-even static form factors ∆κ V and ∆QV (V = γ, Z) associated with the W W V vertex are studied in the context of the Georgi-Machacek model (GMM), which predicts nine new scalar bosons accommodated in a singlet, a triplet and a fiveplet. General expressions for the one-loop contributions to ∆κ V and ∆QV arising from neutral, singly and doubly charged scalar bosons are obtained in terms of both parametric integrals and Passarino-Veltman scalar functions, which can be numerically evaluated. It is found that the GMM yields 15 (28) distinct contributions to ∆κ γ and ∆Qγ (∆κ Z and ∆QZ ), though several of them are naturally suppressed. A numerical analysis is done in the region of parameter space still consistent with current experimental data and it is found that the largest contributions to ∆κ V arise from Feynman diagrams with two nondegenerate scalar bosons in the loop, with values of the order of a = g 2 /(96π 2 ) reached when there is a large splitting between the masses of these scalar bosons. As for ∆QV , it reaches values as large as 10 −2 a for the lightest allowed scalar bosons, but it decreases rapidly as one of the masses of the scalar bosons becomes large. Among the new contributions of the GMM to the ∆κ V and ∆QV form factors are those induced by the H ± 5 W ∓ Z vertex, which arises at the tree-level and is a unique prediction of this model.

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Automatic predictions in the Georgi-Machacek model at next-to-leading order accuracy

Cited by 40 publications

References 173 publications

Light (and darkness) from a light hidden Higgs

Light (and darkness) from a light hidden Higgs

A UV complete compositeness scenario: LHC constraints meet the lattice

WWV ( V=γ , Z ) vertex in the Georgi-Machacek model

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