Revisit of the electromagnetic correction to τ → π π ν τ and its implication for muon g − 2 based on τ data
Year: 2025
Type: erratum
Abstract: In this work we focus on the evaluation of the leading-order hadronic vacuum polarization contribution from the π π channel to the muon anomalous magnetic moment a μ by using the experimental τ → π π ν τ data. The isospin breaking corrections play the decisive role in this approach of computing a μ . One of such important isospin breaking sources is the long-distance electromagnetic correction factor G EM of the τ → π π ν τ process from the real photon radiation. The latter effect can be calculated from the τ → π π ν τ γ amplitude, which is revised in this work within the resonance chiral theory by simultaneously including the even-intrinsic-parity and odd-intrinsic-parity resonance operators. We update the determination of the only unknown resonance coupling through the ω → π 0 π 0 γ decay by including contributions from both the vector and scalar resonances. By taking other remaining contributions from the muon g − 2 White Paper 2025, we further revise the complete value of a μ , which turns out to deviate from the newest world average result after Fermilab’s measurement at the level of 2.7 σ .
DOI: 10.1103/j9wc-wgd9
Authors: Zhi-Xin Li, Ao Li, Jin Hao, Chun-Gui Duan, Zhi-Hui Guo
Institution: Hebei Normal University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Awards: G507716081, G6653449898, G8733112629, G91386230
OpenAlex ID: W4417467854