arXiv subjects

T. Binoth

Publications and source records attributed to T. Binoth.

62 records · Page 4Linked to original sources

arXiv1997

NLO correction to Higgs boson parameters in the 1/N expansion

We present the result of a calculation of the next-to-leading correction to the Higgs propagator in the 1/N expansion, where the Higgs sector is treated as an O(N) symmetric sigma-model. The results are compared with two-loop perturbation theory. The existing discrepancy between the lowest order of the 1/N expansion and perturbation theory is dramatically reduced by including the NLO in 1/N. We find a maximum effective Higgs mass of 930-980 GeV. We give an approximate relation between Higgs width and mass, which can be used for phenomenological purposes.

hep-ph↗

arXiv1997

Nonperturbative Higgs propagator: NLO correction in the 1/N expansion

We derive a nonperturbative result for the Higgs propagator by calculating the NLO correction in the 1/N expansion of O(N) sigma models. For dealing with the 1/N expansion beyond leading order, we develop techniques to calculate certain infinite sets of multiloop Feynman diagrams. We then calculate the Higgs lineshape in fermion scattering, as seen for instance at a muon collider. We compare with the existing two-loop perturbative results. There is a considerable discrepancy between perturbation theory and the 1/N expansion in LO. By including the NLO correction, this discrepancy is reduced dramatically. The results are in very good agreement with the two-loop result even for masses as high as 850 GeV. A maximum of the mass is reached at 930 GeV. For phenomenological purposes, we give a simple approximate relation between the Higgs mass and width.

hep-ph↗

arXiv1997

On the position of a heavy Higgs pole

Higher loop calculations in the Higgs sector of the standard model at the Higgs mass scale have shown that perturbation theory diverges very badly at about 1 TeV in the on-shell renormalization scheme. The prediction of the position of the Higgs pole in the complex s-plane becomes unreliable. We show that in the pole renormalization scheme this appears to have much better convergence properties, while showing good agreement with the on-shell scheme over the validity range of the latter. This suggests that the pole scheme should be preferable for phenomenological studies of heavy Higgs bosons. We discuss whether this behaviour can be the result of a certain relation between the on-shell mass and the pole mass at the nonperturbative level.

hep-ph↗

arXiv1997

Radiative corrections to the lineshape of a heavy Higgs boson at muon colliders

We study the NNLO radiative corrections of enhanced electroweak strength to the lineshape of the Higgs boson in the processes ($μ^+μ^- \to H \to ZZ$) and ($μ^+μ^- \to H \to t\bar t$), which are of interest for Higgs searches at a possible muon collider. We give the radiative corrections both in the on-shell renormalization scheme and in the pole renormalization scheme. The pole scheme appears to have better convergence properties, in agreement with previous results regarding the position of the Higgs pole in the complex plane.

hep-ph↗

arXiv1996

Influence of strongly coupled, hidden scalars on Higgs signals

To investigate the possible effects of a light hidden sector on Higgs boson detection, we discuss a model of scalar singlets coupled to the Standard Model. The model effectively makes the Higgs width a free parameter due to additional invisible decay modes. This width can become arbitrarily large. Theoretical and experimental bounds on model parameters are presented. It is shown, how Standard Model predictions change and that in the case of large coupling, Higgs signals will be diluted. We study, to which extent such a strongly coupled, hidden sector can be excluded by present and future Higgs search experiments.

hep-ph↗

arXiv1996

The hidden Higgs model at the NLC

We investigate the influence of massless scalar singlets on Higgs signals at the NLC. An exclusion bound is presented which restricts large regions of the parameter space but on the other hand implies that for strong interactions between the Higgs boson and the singlet fields of the hidden sector, detection of such a non standard Higgs signal can become impossible.

hep-ph↗

arXiv1996

Higgs Physics at LEP2

In this report we review the prospects for Higgs physics at LEP2. The theoretical aspects and the phenomenology of Higgs particles are discussed within the Standard Model (SM) and the Minimal Supersymmetric Standard Model (MSSM). The experimental search techniques are described and the discovery limits for Higgs bosons in the LEP2 energy range are summarized. In addition, opportunities of detecting Higgs particles in non-minimal extensions of the SM and the MSSM are investigated.

hep-ph↗

arXiv1995

The hidden Higgs model at LEP2

The influence of massless scalar singlets on the Higgs signal at LEP2 is discussed. It is shown that for strong interactions between the Higgs boson and the singlet fields, detection of the Higgs signal can become impossible.

hep-ph↗