Work

Top-quark decay at next-to-next-to-next-to-leading order in QCD

Year: 2026

Type: article

Abstract: We present the first complete QCD corrections to the inclusive decay width Γ t , the W -helicity fractions f L , R , 0 and semi-inclusive distributions for the top-quark decay process t → b + W + + X QCD at next-to-next-to-next-to-leading order (NNNLO) in the strong coupling constant α s . In particular, the pure NNNLO QCD correction decreases Γ t by about 0.8% relative to the previous next-to-next-to-leading order (NNLO) result at the scale of the top-quark pole mass, exceeding the uncertainty estimated by the conventional scale-variation prescription. After taking into account errors from various sources, we get Γ t = 1.314 8 − 0.005 + 0.003 × | V t b | 2 + 0.027 ( m t − 172.69 ) GeV , whose uncertainty meets the request of future colliders. On the other hand, the NNNLO QCD effects on f L , R , 0 are found to be much smaller, at the level of one one per mille for the dominant f 0 , making them precision observables for the top-quark decay process.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/dvlc-58hx

Authors: Long Chen, Xiang Chen, Xin Guan, Yan-Qing Ma

Institutions: Shandong University, Peking University

Language: English

Topic: Particle physics theoretical and experimental studies

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: Shandong University, National Natural Science Foundation of China, Peking University, National Key Research and Development Program of China