Techniques for the treatment of IR divergences in decay processes at NLO and application to the top-quark decay

Abstract

We present the extension of two general algorithms for the treatment of infrared singularities arising in electroweak corrections to decay processes at next-to-leading order: the dipole subtraction formalism and the one-cutoff slicing method. The former is extended to the case of decay kinematics which has not been considered in the literature so far. The latter is generalized to production and decay processes with more than two charged particles, where new "surface" terms arise. Arbitrary patterns of massive and massless external particles are considered, including the treatment of infrared singularities in dimensional or mass regularization. As an application of the two techniques we present the calculation of the next-to-leading-order QCD and electroweak corrections to the top-quark decay width including all off-shell and decay effects of intermediate W bosons. The result, e.g., represents a building block of a future calculation of NLO electroweak effects to off-shell top-quark pair (WWbb) production. Moreover, this calculation can serve as the first step towards an event generator for top-quark decays at next-to-leading order accuracy, which can be used to attach top-quark decays to complicated many-particle top-quark processes, such as for tt+H or tt+jets.

37 pages, 8 figures

References in corpus (15)

• First Look at the Physics Case of TLEP
• Scalar one-loop 4-point integrals
• Complete off-shell effects in top quark pair hadroproduction with leptonic decay at next-to-leading order
• The complex-mass scheme for perturbative calculations with unstable particles
• NLO QCD corrections to WWbb production at hadron colliders
• Techniques for the calculation of electroweak radiative corrections at the one-loop level and results for W-physics at LEP200
• NLO QCD corrections to off-shell top-antitop production with leptonic decays at hadron colliders
• Mixed QCD-electroweak O(α_sα) corrections to Drell-Yan processes in the resonance region: pole approximation and non-factorizable corrections
• Polarized QED splittings of massive fermions and dipole subtraction for non-collinear-safe observables
• NLO QCD corrections to W+ W- b anti-b production with leptonic decays in the light of top quark mass and asymmetry measurements
• Measurement of the ratio B(t to Wb)/B(t to Wq) in pp collisions at sqrt(s) = 8 TeV
• A unified NLO description of top-pair and associated Wt production
• A Direct Measurement of the Total Decay Width of the Top Quark
• FormCalc 8: Better Algebra and Vectorization
• Demonstration of One Cutoff Phase Space Slicing Method: Next-to-Leading Order QCD Corrections to the $tW$ Associated Production in Hadron Collision

Cited by in corpus (26)

• The automation of next-to-leading order electroweak calculations
• Electroweak Radiative Corrections for Collider Physics
• Dominant mixed QCD-electroweak $\mathcal{O}({\alpha }_s\alpha )$ corrections to Drell-Yan processes in the resonance region
• NLO electroweak corrections to off-shell top-antitop production with leptonic decays at the LHC
• An automated subtraction of NLO EW infrared divergences
• Higgs production in association with off-shell top-antitop pairs at NLO EW and QCD at the LHC
• Off-shell production of top-antitop pairs in the lepton+jets channel at NLO QCD
• QCD and electroweak corrections to WZ scattering at the LHC
• Parton Shower and Matching Uncertainties in Top Quark Pair Production with Herwig 7
• Fiducial polarization observables in hadronic WZ production: A next-to-leading order QCD+EW study
• $t\bar{t}b\bar{b}$ at the LHC: On the size of corrections and $b$-jet definitions
• Combined NLO EW and QCD corrections to off-shell $\text{t}\overline{\text{t}}\text{W}$ production at the LHC
• Full NLO QCD corrections to off-shell ttbb production
• NLO QCD corrections to off-shell $\text{t}\bar{\text{t}}{\text{W}}^{+}$ production at the LHC
• NLO QCD corrections to full off-shell production of $t\bar{t}Z$ including leptonic decays
• Resonance-improved parton-shower matching for the Drell-Yan process including electroweak corrections
• $t\bar{t}b\bar{b}$ at the LHC: On the size of off-shell effects and prompt $b$-jet identification
• A study of additional jet activity in top quark pair production and decay at the LHC
• Complete NLO corrections to top-quark pair production with isolated photons
• Logarithmic EW corrections at one-loop
• Photon splitting corrections to soft-photon resummation
• Electroweak Loops as a Probe of New Physics in $t\bar{t}$ Production at the LHC
• NLO QCD corrections to off-shell top-antitop production with semi-leptonic decays at lepton colliders
• NLO QCD and EW corrections to off-shell $\mathrm{tZj}$ production at the LHC
• Top-Quark Decay at Next-to-Next-to-Next-to-Leading Order in QCD
• Complete NLO corrections to off-shell $\mathbf{t}\bar{\mathbf{t}}$ production in the $\mathbf{\ell }+\mathbf{j}$ decay channel