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O. Brein

Publications and source records attributed to O. Brein.

11 recordsLinked to original sources
arXiv2011

Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables

This Report summarizes the results of the first 10 months' activities of the LHC Higgs Cross Sections Working Group. The main goal of the working group was to present the status-of-art on Higgs Physics at the LHC integrating all new results that have appeared in the last few years. The Report is more than a mere collection of the proceedings of the general meetings. The subgroups have been working in different directions. An attempt has been made to present the first Report from these subgroups in a complete and homogeneous form. The subgroups' contributions correspondingly comprise the main parts of the Report. A significant amount of work has been performed in providing higher-order corrections to the Higgs-boson cross sections and pinning down the theoretical uncertainty of the Standard Model predictions. This Report comprises explicit numerical results on total cross sections, leaving the issues of event selection cuts and differential distributions to future publications. The subjects for further study are identified.

hep-ph↗
arXiv2009

New HiggsBounds from LEP and the Tevatron

We review the program HiggsBounds that tests theoretical predictions of models with arbitrary Higgs sectors against the exclusion bounds obtained from the Higgs searches at LEP and the Tevatron. We explicitly list the bounds that have been added after the first release of HiggsBounds.

hep-ph↗
arXiv2009

HiggsBounds: Confronting arbitrary Higgs sectors with exclusion bounds from LEP and Tevatron

HiggsBounds is a computer code which tests the Higgs sectors of new models against the current exclusion bounds from the Higgs searches at LEP and the Tevatron. As input, it requires a selection of model predictions, such as Higgs masses, branching ratios, effective couplings and total decay widths. HiggsBounds then uses the expected and observed topological cross section limits from the Higgs searches to determine which points in the parameter space have already been excluded at 95% CL. HiggsBounds will be updated to include new results as they become available.

hep-ph↗
arXiv2005

Charged Higgs Production in Association with W Boson at Photon Colliders

It is important to explore the Higgs sector in order to identify the model beyond the standard model. We study the charged Higgs production in the $γγ$ mode of a linear collider (LC) with 1000 GeV center of mass energy. We show that the cross sections for the $γγ\to H^\pm W^\mp$ processes can be significantly enhanced in the two Higgs doublet model (THDM). The cross section can reach 0.1 - 100 fb which is comparable to other charged Higgs boson production processes at a photon collider. While for other processes the cross sections are too small for $m_H^\pm \geq 500$ GeV, $0.1 - 100$ fb can be expected in the $γγ\to H^\pm W^\mp$ processes for $m_H^\pm \geq 570$ GeV when $m_{A^0}=800$ GeV. Therefore, even if the charged Higgs bosons can not be detected at the Large Hadron Collider (LHC), and even if the charged Higgs bosons are too heavy to be detected in other charged Higgs boson production processes at the LC, it may be possible to detect them in this process.

hep-ph↗
arXiv2004

Radiative Corrections to Deep-Inelastic Neutrino--Nucleon Scattering in the MSSM

We discuss the radiative corrections to charged and neutral current deep-inelastic neutrino--nucleon scattering in the minimal supersymmetric standard model (MSSM). In particular, deviations from the Standard Model prediction for the ratios of neutral- to charged-current cross sections, $R^ν$ and $R^{\barν}$, are studied, and results of a scan over the MSSM parameter space are presented.

hep-ph↗
arXiv2004

The Higgs Working Group: Summary Report 2003

Theoretical progress in Higgs boson production and background processes is discussed with particular emphasis on QCD corrections at and beyond next-to-leading order as well as next-to-leading order electroweak corrections. The residual theoretical uncertainties of the investigated processes are estimated in detail. Moreover, recent investigations of the MSSM Higgs sector and other extensions of the SM Higgs sector are presented. The potential of the LHC and a high-energy linear e+e- collider for the measurement of Higgs couplings is analyzed.

hep-ph↗
arXiv2004

Single Charged MSSM Higgs-boson production at a Linear Collider

In the Minimal Supersymmetric Standard Model we present the calculation of the single charged Higgs-boson production in the gamma W- or Z W-fusion and the charged Higgs strahlung channel, e^+ e^- -> e nu H^\pm. The set of all O(alpha) corrections arising from loops of Standard Model fermions and scalar fermions are taken into account. Contrary to the case of single neutral heavy CP-even Higgs-boson production, for the charged Higgs boson we find for all the parameter space of the typical benchmark scenarios a cross section smaller than \sim 0.01 fb for sqrt(s)/2 \lessim M_H^\pm.

hep-ph↗
arXiv2004

Precision Calculations for Associated WH and ZH Production at Hadron Colliders

Recently the next-to-next-to-leading order QCD corrections and the electroweak O(alpha) corrections to the Higgs-strahlung processes ppbar/pp -> WH/ZH + X have been calculated. Both types of corrections are of the order of 5-10%. In this article the various corrections are briefly discussed and combined into state-of-the-art predictions for the cross sections. The theoretical uncertainties from renormalization/factorization scales and from the parton distribution functions are discussed.

hep-ph↗
arXiv2001

Electroweak Radiative Corrections to Neutral-Current Drell-Yan Processes at Hadron Colliders

We calculate the complete electroweak O(alpha) corrections to pp, pbar p -> l+l- X (l=e, mu) in the Standard Model of electroweak interactions. They comprise weak and photonic virtual one-loop corrections as well as real photon radiation to the parton-level processes q bar q -> gamma,Z -> l+l-. We study in detail the effect of the radiative corrections on the l+l- invariant mass distribution, the cross section in the Z boson resonance region, and on the forward-backward asymmetry, A_FB, at the Fermilab Tevatron and the CERN Large Hadron Collider. The weak corrections are found to increase the Z boson cross section by about 1%, but have little effect on the forward-backward asymmetry in the Z peak region. Threshold effects of the W box diagrams lead to pronounced effects in A_FB at m(l+l-) approx 160 GeV which, however, will be difficult to observe experimentally. At high di-lepton invariant masses, the non-factorizable weak corrections are found to become large.

hep-ph↗
arXiv2000

Pair production of charged MSSM Higgs bosons by gluon fusion

The production of pairs of charged Higgs bosons as predicted by the minimal supersymmetric standard model (MSSM) via the gluon fusion mechanism is investigated. The amplitudes at the leading one-loop order for the parton process gg -> H+ H- are calculated with the complete set of MSSM particles. Numerical results are presented for the cross section of the inclusive hadron process p p -> gg -> H+ H- + X at the LHC.

hep-ph↗