QCD parameters and SM-high precision from $e^+e^-$ to Hadrons: Updated
Abstract
1. I update my previous comparison of the theoretical value of the muon anomaly with the new measurement and found which is about 3 discrepancy between the SM predictions and experiment. 2. I improve the estimate of QCD power corrections up to dimension D=12 and provide a new estimate of the ones up to D=20 within the SVZ expansion by combining the ratio of the Laplace sum rules (LSR) with the BNP -like decay moments for the I=1 vector current. The results in Table 1 confirm a violation of the factorization of the four-quark condensates and the value of the gluon one from some other sources. Up to D=20, I there is not any factorial nor exponential growth of the size of these power corrections. 3. I use these new values of power corrections to extract from the BNP lowest moment. To order , I find within the SVZ expansion: [resp. implying [resp. ] for Fixed Order (FO) [resp. Contour Improved (CI)] PT series. They lead to the mean: and where the systematic error(syst) takes into account the discrepancy between FO and CI. Using the lowest BNP moment, we also obtain from the vector (V) component of -decay the mean: giving: . The average of the two determinations leads to: and . 4. Some contributions beyond the SVZ expansion (, instantons and duality violation) expected to be small are discussed in Sections 10,11.
Cite
@article{arxiv.2402.13983,
title = {QCD parameters and SM-high precision from $e^+e^-$ to Hadrons: Updated},
author = {Stephan Narison},
journal= {arXiv preprint arXiv:2402.13983},
year = {2024}
}
Comments
Latex sources, 19 pages, 8 figures, 3 tables. Some preliminaries results have been presented at the alphas2024 workshop (5-9th february 2024-ECT*-Trento-IT). Section 9 on the determination of alpha_s from tau-decay has been corrected. Version published in Nucl. Phys. A + Corrigendum (to appear in Nucl. Phys. A)