Two-Loop Threshold Singularities, Unstable Particles and Complex Masses

Abstract

The effect of threshold singularities induced by unstable particles on two-loop observables is investigated and it is shown how to cure them working in the complex-mass scheme. The impact on radiative corrections around thresholds is thoroughly analyzed and shown to be relevant for two selected LHC and ILC applications: Higgs production via gluon fusion and decay into two photons at two loops in the Standard Model. Concerning Higgs production, it is essential to understand possible sources of large corrections in addition to the well-known QCD effects. It is shown that NLO electroweak corrections can incongruently reach a 10 % level around the WW vector-boson threshold without a complete implementation of the complex-mass scheme in the two-loop calculation.

LaTeX, 12 pages, 7 figures

References in corpus (10)

• NLO Electroweak Corrections to Higgs Boson Production at Hadron Colliders
• The complex-mass scheme for perturbative calculations with unstable particles
• Two-Loop Renormalization in the Standard Model Part III: Renormalization Equations and their Solutions
• Four-fermion production near the W pair production threshold
• Two-Loop Renormalization in the Standard Model Part I: Prolegomena
• Complete Two-Loop Corrections to H -> gamma gamma
• Dominant NNLO corrections to four-fermion production near the W-pair production threshold
• Two-Loop Renormalization in the Standard Model Part II: Renormalization Procedures and Computational Techniques
• Two-Loop Vertices in Quantum Field Theory: Infrared and Collinear Divergent Configurations
• b anti-b Higgs production at the LHC: Yukawa corrections and the leading Landau singularity

Cited by in corpus (26)

• NLO Electroweak Corrections to Higgs Boson Production at Hadron Colliders
• Golem95C: A library for one-loop integrals with complex masses
• The Higgs Boson Lineshape
• Higgs Pseudo-Observables, Second Riemann Sheet and All That
• The Complex-Mass Scheme and Unitarity in perturbative Quantum Field Theory
• Higgs Boson Production and Decay: Dalitz Sector
• Complex-mass renormalization in chiral effective field theory
• Magnetic moment of the Roper resonance
• Electromagnetic transition form factors of the Roper resonance in effective field theory
• The Higgs Boson in the Standard Model - From LEP to LHC: Expectations, Searches, and Discovery of a Candidate
• Impact of Electroweak Corrections on Neutral Higgs Boson Decays in Extended Higgs Sectors
• Decays of Higgs Bosons in the Standard Model and Beyond
• Path integral quantization for massive vector bosons
• Complex-mass scheme and perturbative unitarity
• Vector form factor of the pion in chiral effective field theory
• Nucleon-to-Delta transition form factors in chiral effective field theory using the complex-mass scheme
• Measuring Supersymmetry with Heavy Scalars
• Effective field theory approach to the Higgs lineshape
• NLO electroweak corrections in general scalar singlet models
• Standard SANC modules for NLO QCD Radiative Corrections to Single-top Production
• Mass and width of the $\Delta (1232)$ resonance using complex-mass renormalization
• Estimations for the Single Diffractive production of the Higgs boson at the Tevatron and the LHC
• Chiral effective field theories of the strong interactions
• Electroweak corrections to $g+g\to H_{l,h}$ and $H_{l,h}\to \gamma +\gamma$ in the Higgs-singlet extension of the Standard model
• Estimations for the Higgs boson production with QCD and EW corrections in exclusive events at the LHC
• Axial-vector nucleon-to-delta transition form factors using the complex-mass renormalization scheme