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Main Authors: Yan, Jiang, Wu, Xing-Gang, Zhou, Hua, Li, Hong-Tai, Shan, Jing-Hao
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2404.11133
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author Yan, Jiang
Wu, Xing-Gang
Zhou, Hua
Li, Hong-Tai
Shan, Jing-Hao
author_facet Yan, Jiang
Wu, Xing-Gang
Zhou, Hua
Li, Hong-Tai
Shan, Jing-Hao
contents In this paper, we analyze the top-quark decay $t\to Wb$ up to next-to-next-to-next-to-leading order (N$^{3}$LO) QCD corrections. For the purpose, we first adopt the principle of maximum conformality (PMC) to deal with the initial pQCD series. Then we adopt the Bayesian analysis approach, which quantifies the unknown higher-order terms' contributions in terms of a probability distribution, to estimate the possible magnitude of the uncalculated N$^{4}$LO-terms. In our calculation, an effective strong coupling constant $α_{s}(Q_{*})$ is determined by using all non-conformal $\{β_{i}\}$ terms associated with the renormalization group equation. This leads to a next-to-leading-log PMC scale $Q_{*}^{(\rm NLL)}=10.3048$ GeV, which can be regarded as the correct momentum flow of the process. Consequently, we obtain an improved scale-invariant pQCD prediction for the top-quark decay width, e.g. $Γ_{t}^{\rm tot} = 1.3120 \pm 0.0038$ GeV, whose error is the squared average of the uncertainties from the decay width of $W$-boson $ΔΓ_{W} = \pm 0.042$ GeV, the coupling constant $Δα_{s}(m_{Z}) = \pm 0.0009$, and the predicted N$^{4}$LO-terms. The magnitude of the top-quark pole mass greatly affects the total decay width. By further taking the PDG top-quark pole mass error from cross-section measurements into consideration, e.g. $Δm_{t} = \pm 0.7$ GeV, we obtain $Γ_{t}^{\rm tot} = 1.3120 ^{+0.0194}_{-0.0192}$ GeV.
format Preprint
id arxiv_https___arxiv_org_abs_2404_11133
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Improved analysis of the decay width of $t\to Wb$ up to N$^{3}$LO QCD corrections
Yan, Jiang
Wu, Xing-Gang
Zhou, Hua
Li, Hong-Tai
Shan, Jing-Hao
High Energy Physics - Phenomenology
In this paper, we analyze the top-quark decay $t\to Wb$ up to next-to-next-to-next-to-leading order (N$^{3}$LO) QCD corrections. For the purpose, we first adopt the principle of maximum conformality (PMC) to deal with the initial pQCD series. Then we adopt the Bayesian analysis approach, which quantifies the unknown higher-order terms' contributions in terms of a probability distribution, to estimate the possible magnitude of the uncalculated N$^{4}$LO-terms. In our calculation, an effective strong coupling constant $α_{s}(Q_{*})$ is determined by using all non-conformal $\{β_{i}\}$ terms associated with the renormalization group equation. This leads to a next-to-leading-log PMC scale $Q_{*}^{(\rm NLL)}=10.3048$ GeV, which can be regarded as the correct momentum flow of the process. Consequently, we obtain an improved scale-invariant pQCD prediction for the top-quark decay width, e.g. $Γ_{t}^{\rm tot} = 1.3120 \pm 0.0038$ GeV, whose error is the squared average of the uncertainties from the decay width of $W$-boson $ΔΓ_{W} = \pm 0.042$ GeV, the coupling constant $Δα_{s}(m_{Z}) = \pm 0.0009$, and the predicted N$^{4}$LO-terms. The magnitude of the top-quark pole mass greatly affects the total decay width. By further taking the PDG top-quark pole mass error from cross-section measurements into consideration, e.g. $Δm_{t} = \pm 0.7$ GeV, we obtain $Γ_{t}^{\rm tot} = 1.3120 ^{+0.0194}_{-0.0192}$ GeV.
title Improved analysis of the decay width of $t\to Wb$ up to N$^{3}$LO QCD corrections
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2404.11133