Determining $\alpha_s$ from hadronic $\tau$ decay: the pitfalls of truncating the OPE

Boito, Diogo; Golterman, Maarten; Maltman, Kim; Peris, Santiago

doi:10.21468/SciPostPhysProc.1.053

SciPost Physics Proceedings

Determining $\alpha_s$ from hadronic $\tau$ decay: the pitfalls of truncating the OPE

Diogo Boito, Maarten Golterman, Kim Maltman, Santiago Peris

SciPost Phys. Proc. 1, 053 (2019) · published 22 February 2019

doi: 10.21468/SciPostPhysProc.1.053
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The 15th International Workshop on Tau Lepton Physics

Abstract

We discuss sum-rule determinations of $\alpha_s$ from non-strange hadronic $\tau$-decay data. We investigate, in particular, the reliability of the assumptions underlying the ``truncated OPE strategy,'' which specifies a certain treatment of non-perturbative contributions, and which was employed in Refs.~\cite{Pich,Aleph, Opal}. Here, we test this strategy by applying the strategy to the $R$-ratio obtained from $e^+e^-$ data, which extend beyond the $\tau$ mass, and demonstrate that the assumptions underlying this strategy are not, in general, valid. We then present a brief overview of new results on the form of duality-violating non-perturbative contributions, which are conspicuously present in the experimentally determined spectral functions. As we show, with the current precision claimed for the extraction of $\alpha_s$, including a representation of duality violations is unavoidable if one wishes to avoid uncontrolled theoretical errors.

TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhysProc.1.053
TI  - Determining $\alpha_s$ from hadronic $\tau$ decay: the pitfalls of truncating the OPE
PY  - 2019/02/22
UR  - https://scipost.org/SciPostPhysProc.1.053
JF  - SciPost Physics Proceedings
JA  - SciPost Phys. Proc.
VL  - 
IS  - 1
SP  - 053
A1  - Boito, Diogo
AU  - Golterman, Maarten
AU  - Maltman, Kim
AU  - Peris, Santiago
AB  - We discuss sum-rule determinations of $\alpha_s$ from non-strange hadronic $\tau$-decay data. We investigate, in particular, the reliability of the assumptions underlying the ``truncated OPE strategy,'' which specifies a certain treatment of non-perturbative contributions, and which was employed in Refs.~\cite{Pich,Aleph, Opal}. Here, we test this strategy by applying the strategy to the $R$-ratio obtained from $e^+e^-$ data, which extend beyond the $\tau$ mass, and demonstrate that the assumptions underlying this strategy are not, in general, valid. We then present a brief overview of new results on the form of duality-violating non-perturbative contributions, which are conspicuously present in the experimentally determined spectral functions. As we show, with the current precision claimed for the extraction of $\alpha_s$, including a representation of duality violations is unavoidable if one wishes to avoid uncontrolled theoretical errors.
ER  -

@Article{10.21468/SciPostPhysProc.1.053,
	title={{Determining $\alpha_s$ from hadronic $\tau$ decay: the pitfalls of truncating the OPE}},
	author={Diogo Boito and Maarten Golterman and Kim Maltman and Santiago Peris},
	journal={SciPost Phys. Proc.},
	pages={053},
	year={2019},
	publisher={SciPost},
	doi={10.21468/SciPostPhysProc.1.053},
	url={https://scipost.org/10.21468/SciPostPhysProc.1.053},
}

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