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Strong coupling at the $\tau$-mass scale from an improved vector isovector spectral function
by Diogo Boito, Maarten Golterman, Kim Maltman, Santiago Peris, Marcus V. Rodrigues, Wilder Schaaf
Submission summary
| Authors (as registered SciPost users): | Diogo Boito |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202112_00034v1 (pdf) |
| Date accepted: | 2024-12-11 |
| Date submitted: | 2021-12-14 16:56 |
| Submitted by: | Boito, Diogo |
| Submitted to: | SciPost Physics Proceedings |
| Proceedings issue: | 16th International Workshop on Tau Lepton Physics (TAU2021) |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approach: | Phenomenological |
Abstract
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 fromelectroproduction 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 $\alpha_s(m_\tau)=0.3077\pm0.0075$, which corresponds to $\alpha_s(m_Z)=0.1171\pm0.0010$. 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.
Current status:
Editorial decision:
For Journal SciPost Physics Proceedings: Publish
(status: Editorial decision fixed and (if required) accepted by authors)
Reports on this Submission
Report #1 by Swagato Banerjee (Referee 1) on 2024-11-29 (Invited Report)
Report
A new vector isovector spectral function has been developed based on a combination of the ALEPH and OPAL spectra for the dominant ππ0, π3π0, and 3ππ0 τ decay channels, supplemented by the addition of contributions from all numerically significant residual decay modes, for example τ → K−K0ντ from BaBar, and a wealth of recent CVC-related cross- section results from e+e− → hadrons obtained by CMD-3, SND and BaBar. Finite energy sum rules are analyzed to extract the value of the strong coupling at the tau mass scale, which is very competitive from other measurements. The methodology could be improved with new measurements for the spectral distributions of the dominant vector τ decay channels in the future.
Recommendation
Publish (surpasses expectations and criteria for this Journal; among top 10%)