Radiative corrections to the Higgs boson couplings in the triplet model

Abstract

We calculate a full set of one-loop corrections to the Higgs boson coupling constants as well as the electroweak parameters. We compute the decay rate of the standard model (SM)-like Higgs boson (h) into diphoton. Renormalized Higgs couplings with the weak gauge bosons hV V (V = W and Z) and the trilinear coupling hhh are also calculated at the one-loop level in the on-shell scheme. Magnitudes of the deviations in these quantities are evaluated in the parameter regions where the unitarity and vacuum stability bounds are satisfied and the predicted W boson mass at the one-loop level is consistent with the data. We find that there are strong correlations among deviations in the Higgs boson couplings hγγ, hV V and hhh. For example, if the event number of the pp → h → γγ channel deviates by +30% (−40%) from the SM prediction, deviations in the one-loop corrected hV V and hhh vertices are predicted about −0.1% (−2%) and −10% (+150%), respectively. The model can be discriminated from the other models by measuring these coupling constants accurately at future collider experiments.

LHC phenomenology of the type II seesaw mechanism: Nondegenerate case

“…A careful analysis of oneloop radiative corrections has been made in Ref. [36], and the result turns out to depend significantly on the renormalization scheme employed. In the so-called scheme I, one employs the effective mixing angle θ e eff defined by the Zee vertex as the fourth input parameter in the gauge sector.…”

“…In the scheme II, one adopts instead the mixing angle α between A 0 and G 0 as the fourth input parameter. It was found [36] that for v ∆ 1 GeV the positive and negative scenarios can be accommodated with ∆M 50, 30 GeV respectively. This result is consistent with the bound from the electroweak S, T , U parameters [37], which requires ∆M 40 GeV, independently of the doubly charged scalar mass.…”

Revisiting the high-scale validity of the type II seesaw model with novel LHC signature

“…The value of v t is highly constrained by the ρ-parameter and quantitatively it cannot be larger than a few GeV [27]. This has a greater implication on the decay modes of the singly and doubly charged scalars.…”

“…However, the total width will mainly be modified by the loop-induced decay modes h → γγ where the nonstandard singly and doubly charged scalar may contribute significantly. Some detailed studies have already been performed in this respect [9,11,15,27,[56][57][58]. Here we will refrain ourselves from giving an elaborate description except a comment on the parameter space and for the collider study, our choice of benchmark points remain within the 2σ limit of the current experimental bound of the Higgs to diphoton signal strength [59].…”

“…(iii) Constraints from electroweak precision test The new triplet Higgs bosons contribute to the electroweak precision observables, namely, the S,T, U parameters [27,49]. The strongest bound comes from the T-parameter which imposes strict limit on the mass splitting between the doubly and singly charged scalars, ΔM ≡ jm H AEAE − m H AE j which should be ≲50 GeV [9,24] assuming a light SM Higgs boson of mass m h ¼ 125 GeV and top quark mass M t ¼ 173 GeV.…”