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Extraction of $\alpha_s$ using Borel-Laplace sum rules for tau decay data
- Publication Year :
- 2022
-
Abstract
- Double-pinched Borel-Laplace sum rules are applied to ALEPH $\tau$-decay data. For the leading-twist ($D=0$) Adler function a renormalon-motivated extension is used, and the 5-loop coefficient is taken to be $d_4=275 \pm 63$. Two $D=6$ terms appear in the truncated OPE ($D \leq 6$) to enable cancellation of the corresponding renormalon ambiguities. Two variants of the fixed order perturbation theory, and the inverse Borel transform, are applied to the evaluation of the $D=0$ contribution. Truncation index $N_t$ is fixed by the requirement of local insensitivity of the momenta $a^{(2,0)}$ and $a^{(2,1)}$ under variation of $N_t$. The averaged value of the coupling obtained is $\alpha_s(m_{\tau}^2)=0.3235^{+0.0138}_{-0.0126}$ [$\alpha_s(M_Z^2)=0.1191 \pm 0.0016$]. The theoretical uncertainties are significantly larger than the experimental ones.<br />Comment: 4 pages, 1 figure, based on a presentation at: "alphas-2022: Workshop on precision measurements of the QCD coupling constant," January 31 - February 4, 2022, ECT* Trento, Italy; written for the Snowmass-2022 White Paper (The strong coupling constant: State of the art and the decade ahead)
- Subjects :
- High Energy Physics - Phenomenology
Subjects
Details
- Database :
- arXiv
- Publication Type :
- Report
- Accession number :
- edsarx.2202.13178
- Document Type :
- Working Paper