TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhysProc.16.004
TI  - Strong coupling at the $\tau$-mass scale from an improved vector isovector spectral function
PY  - 2025/07/14
UR  - https://scipost.org/SciPostPhysProc.16.004
JF  - SciPost Physics Proceedings
JA  - SciPost Phys. Proc.
VL  - 
IS  - 16
SP  - 004
A1  - Boito, Diogo
AU  - Golterman, Maarten
AU  - Maltman, Kim
AU  - Peris, Santiago
AU  - Gonzalez Rodrigues, Marcus Vinicius
AU  - Schaaf, Wilder
AB  - We perform a precise extraction of the QCD coupling at the $\tau$-mass scale, $\alpha_s(m_\tau)$, from a new vector isovector spectral function which combines ALEPH and OPAL distributions for the dominant channels, $\tau\to\pi \pi^0\nu_\tau$, $\tau\to 3\pi \pi^0\nu_\tau$ and $\tau\to \pi 3\pi^0\nu_\tau$, with estimates of sub-leading contributions obtained from electroproduction cross-sections using CVC, as well as BaBar results for $\tau \to K^-K^0\nu_\tau$. The fully inclusive spectral function thus obtained is entirely based on experimental data, without Monte Carlo input. From this new data set, we obtain $\alpha_s(m_\tau)=0.3077±0.0075$, which corresponds to $\alpha_s(m_Z)=0.1171±0.0010$. This analysis can be improved on the experimental side with new measurements of the dominant $\pi\pi^0$, $\pi 3\pi^0$, and $3\pi \pi^0$ $\tau$ decay modes.
ER  -

@Article{10.21468/SciPostPhysProc.16.004,
	title={{Strong coupling at the $\tau$-mass scale from an improved vector isovector spectral function}},
	author={Diogo Boito and Maarten Golterman and Kim Maltman and Santiago Peris and Marcus V. Rodrigues and Wilder Schaaf},
	journal={SciPost Phys. Proc.},
	pages={004},
	year={2025},
	publisher={SciPost},
	doi={10.21468/SciPostPhysProc.16.004},
	url={https://scipost.org/10.21468/SciPostPhysProc.16.004},
}