Two-loop heavy top corrections to the Z boson partial widths

Abstract

We present the evaluation of the two-loop O(g^4 mt^2) effects in the partial widths of the Z boson in the MSbar scheme and in two different implementations of the on-shell scheme. We observe a clear reduction of the scheme dependence of the predictions. The renormalization procedure and the Heavy Top Expansion employed in the O(g^4 mt^2) calculations are illustrated in some detail and intermediate results are provided. We discuss the implication of our results on the constraints for the Higgs mass making use of simple interpolating formulas. We find that precision data give mh < 285 GeV at 95% C.L. taking into account the theory uncertainty. Including also the information from direct search experiments we obtain a 95% upper bound mh < 345 GeV.

31 pages, 3 figs, new discussion of effects for hadronic widths, minor modifications; accepted by NPB

Cited by in corpus (42)

• The Anatomy of Electro-Weak Symmetry Breaking. I: The Higgs boson in the Standard Model
• Physics with the KLOE-2 experiment at the upgraded DA$\varphi$NE
• Updated Status of the Global Electroweak Fit and Constraints on New Physics
• The muon $g$-2 and $\Delta \alpha$ connection
• Revisiting the Global Electroweak Fit of the Standard Model and Beyond with Gfitter
• The Minimal Supersymmetric Fat Higgs Model
• The Standard Model Prediction of the Muon Anomalous Magnetic Moment
• Electroweak Precision Observables, New Physics and the Nature of a 126 GeV Higgs Boson
• Precise Prediction for M_W in the MSSM
• Old and new physics interpretations of the NuTeV anomaly
• ZFITTER: a semi-analytical program for fermion pair production in e+e- annihilation, from version 6.21 to version 6.42
• The muon g-2 and the bounds on the Higgs boson mass
• Theory of the tau lepton anomalous magnetic moment
• MS Versus Pole Masses of Gauge Bosons II: Two-Loop Electroweak Fermion Corrections
• How Can a Heavy Higgs Boson be Consistent with the Precision Electroweak Measurements?
• $\text{HEPfit}$: a Code for the Combination of Indirect and Direct Constraints on High Energy Physics Models
• Higher-order electroweak corrections to the partial widths and branching ratios of the Z boson
• Complete electroweak two-loop corrections to Z boson production and decay
• Impact of the recent measurements of the top-quark and W-boson masses on electroweak precision fits
• MS vs. Pole Masses of Gauge Bosons: Electroweak Bosonic Two-Loop Corrections
• An Approach Toward the Numerical Evaluation of Multi-Loop Feynman Diagrams
• Global analysis of electroweak data in the Standard Model
• Electroweak Precision Tests of the Standard Model after the Discovery of the Higgs Boson
• Z Pole Observables in the MSSM
• Radiative Corrections in Precision Electroweak Physics: a Historical Perspective
• The precision electroweak data in warped extra-dimension models
• Two-loop renormalization of the electric charge in the Standard Model
• Electron, muon and tau magnetic moments: a theoretical update
• Two-loop fermionic electroweak corrections to the Z-boson width and production rate
• Violation of custodial symmetry from W-boson mass measurements
• Simple Formulae for Sin^2 theta_eff^lept, M_W, Gamma_l, and their Physical Applications
• Higgs boson phenomenology and VEV shift in the RS scenario
• Numerical multi-loop integrals and applications
• Status of the Standard Model Prediction of the Muon g-2
• Prospects for e+e- physics at Frascati between the phi and the psi
• W mass and Leptonic Z-decays in the NMSSM
• The tau lepton anomalous magnetic moment
• The muon g-2 discrepancy: new physics or a relatively light Higgs?
• Electroweak Precision Observables within a Fourth Generation Model with General Flavour Structure
• Thirty Years of Precision Electroweak Physics
• Where is the Higgs?
• Predictions for Fermion Pair Production at e+e- Colliders