Gluon-fusion Higgs production at NNLO for a non-standard Higgs sector

107

With the renewed interest in vector-like fermion extensions of the Standard Model, we present here a study of multiple vector-like theories and their phenomenological implications. Our focus is mostly on minimal flavor conserving theories that couple the vector-like fermions to the SM gauge fields and mix only weakly with SM fermions so as to avoid flavor problems. We present calculations for precision electroweak and vector-like state decays, which are needed to investigate compatibility with currently known data. We investigate the impact of vector-like fermions on Higgs boson production and decay, including loop contributions, in a wide variety of vector-like extensions and their parameter spaces.

Section: Jhep09(2014)130 5 Higgs Production and Decay Processesmentioning

confidence: 99%

Survey of vector-like fermion extensions of the Standard Model and their phenomenological implications

Ellis

Godbole

Gopalakrishna

et al. 2014

107

“…The effective unrenormalized Lagrangian reads: 9) where the first term corresponds to an effective QCD Lagrangian with N f = 5 flavors. The Wilson coefficient C can be cast as a function of the QCD coupling, the bare heavy-quark masses and the Higgs field vacuum expectation value [25][26][27][28][29]. Performing a loop-expansion of the amplitudes…”

Section: Jhep12(2013)088mentioning

confidence: 99%

Real-virtual contributions to the inclusive Higgs cross-section at N3LO

Anastasiou

Duhr

Dulat

et al. 2013

102

Abstract:We compute the contributions to the N 3 LO inclusive Higgs boson cross-section from the square of one-loop amplitudes with a Higgs boson and three QCD partons as external states. Our result is a Taylor expansion in the dimensional regulator ǫ, where the coefficients of the expansion are analytic functions of the ratio of the Higgs boson mass and the partonic center of mass energy and they are valid for arbitrary values of this ratio. We also perform a threshold expansion around the limit of soft-parton radiation in the final state. The expressions for the coefficients of the threshold expansion are valid for arbitrary values of the dimension. As a by-product of the threshold expansion calculation, we have developed a soft expansion method at the integrand level by identifying the relevant soft and collinear regions for the loop-momentum.

“…Although they contribute to the hgg coupling, there is a cancellation at low energies which renders this coupling insensitive to the mass and coupling of the top-partner [38][39][40][41][42]. Instead, the coupling is only sensitive to v 2 /f 2 , where f is the scale of breaking of the global symmetry leading to the pseudo-Goldstone sector.…”

Section: Introductionmentioning

confidence: 99%

Probing top-partners in Higgs+jets

Banfi

Martin

Sanz

2014

Fermionic top-partners arise in models such as Composite Higgs and Little Higgs. They modify Higgs properties, in particular how the Higgs couples to top quarks. Alas, there is a low-energy cancellation acting in the coupling of the Higgs boson to gluons and photons. As a result of this cancellation, no information about the spectrum and couplings of the top-partners can be obtained in gg → h, just the overall new physics scale f . In this paper we show that this is not the case when hard radiation is taken into account. Indeed, differential distributions in Higgs plus jets are sensitive to the top-partner mass and coupling to the Higgs. We exploit the transverse momentum distribution of the hard jet to estimate limits on the top-partners in the 14 TeV LHC run. Relying on h → γγ events alone, we find mixing angles of sin 2 (θ R ) 0.2 can be probed after 3000 fb −1 of 14 TeV LHC data. Including other modes, the sensitivity improves, up to sin 2 (θ R ) 0.05 after 300 fb −1 .