Analytic result for the top-quark width at next-to-next-to-leading order in QCD

Abstract

We present the first full analytic results of next-to-next-to-leading order (NNLO) QCD corrections to the top-quark decay width $\Gamma (t\to Wb)$ by calculating the imaginary part of three-loop top-quark self-energy diagrams. The results are all expressed in terms of harmonic polylogarithms and valid in the whole region $0\le m_W^2\le m_t^2$. The expansions in the $m_W^2\to 0$ and $m_W^2\to m_t^2$ limits coincide with previous studies. Our results can also be taken as the exact prediction for the lepton invariant mass spectrum in semileptonic $b\to u$ decays. We also analytically compute the decay width including the off-shell $W$ boson effect up to NNLO in QCD for the first time. Combining these contributions with electroweak corrections and the finite $b$-quark mass effect, we determine the most precise top-quark width to be 1.331 GeV for $m_t=172.69$ GeV. The total theoretical uncertainties including those from renormalization scale choice, top-quark renormalization scheme, input parameters, and missing higher-order corrections are scrutinized and found to be less than $1\%$.

arXiv comment8 pages, 3 figures; v2: matching the published version in PRD

References in corpus (34)

• Generating Feynman Diagrams and Amplitudes with FeynArts 3
• Observation of Top Quark Production in Pbar-P Collisions
• Observation of the Top Quark
• Harmonic Polylogarithms
• Multiloop integrals in dimensional regularization made simple
• FeynCalc 9.3: New features and improvements
• FIRE6: Feynman Integral REduction with Modular Arithmetic
• The QCD Running Coupling
• AMFlow: a Mathematica package for Feynman integrals computation via Auxiliary Mass Flow
• A Systematic and Efficient Method to Compute Multi-loop Master Integrals
• Top-Quark Decay at Next-to-Next-to-Leading Order in QCD
• Complete 2-loop Quantum Electrodynamic Contributions to the Muon Lifetime in the Fermi Model
• Helicity fractions of W bosons from top quark decays at NNLO in QCD
• On the Precise Determination of the Fermi Coupling Constant from the Muon Lifetime
• Can the QCD running coupling have a causal analyticity structure?
• Multi-parameter fits to the t-tbar threshold observables at a future e+e- linear collider
• $O({\alpha }_s^2)$ corrections to fully-differential top quark decays
• Detailed Report of the MuLan Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant
• Second Order QCD Corrections to $\Gamma (t\to Wb)$
• The second order QCD contribution to the semileptonic b -> u decay rate
• Two-loop QCD corrections to top quark width
• Measurement of the ratio B(t to Wb)/B(t to Wq) in pp collisions at sqrt(s) = 8 TeV
• Top-Quark Physics at the CLIC Electron-Positron Linear Collider
• Next-to-leading power endpoint factorization and resummation for off-diagonal "gluon" thrust
• Heavy-to-light decays with a two-loop accuracy
• Next-to-next-to-leading order calculations for heavy-to-light decays
• Pole mass renormalon and its ramifications
• Semileptonic b --> u decays: lepton invariant mass spectrum
• Extracting the Top-Quark Width from Non-Resonant Production
• NNLO QCD corrections to the polarized top quark decay $t(\uparrow )\to X_b+W^{+}$
• Model independent top quark width measurement using a combination of resonant and non resonant cross sections
• Probing the top-quark width using the charge identification of $b$ jets
• QCD improved top-quark decay at next-to-next-to-leading order
• Top quark mass measurements at the $t\bar{t}$ threshold with CEPC

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