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Related papers: $\alpha_{s}$ from the (revised) ALEPH data for $\t…

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The determination of alpha_s from hadronic tau decays is impeded by the fact that two choices for the renormalisation group resummation, namely fixed-order (FOPT) and contour-improved perturbation theory (CIPT), yield systematically…

High Energy Physics - Phenomenology · Physics 2015-05-20 Matthias Jamin

The determination of alpha_s(M_Z^2) using O(alpha_s^2) calculations of hadronic event observables in e+e- annihilation is reviewed. The large scatter among alpha_s(M_Z^2) values determined from different observables may be interpreted as…

High Energy Physics - Experiment · Physics 2007-05-23 P. N. Burrows

We investigate higher-order perturbative corrections to hadronic $\tau$ decays by applying nonlinear sequence-transformation techniques to the QCD correction $\delta^{(0)}$. In particular, we employ the Shanks transformation and several of…

High Energy Physics - Phenomenology · Physics 2026-05-06 Gauhar Abbas , Vartika Singh

The QCD corrections to the moments of the invariant mass distribution in the semileptonic $\tau$ decays are considered. The effect of the renormalization scheme dependence on the fitted values of alpha_s(m^2_tau) and the condensates is…

High Energy Physics - Phenomenology · Physics 2016-08-25 P. A. Raczka

The semihadronic tau decay width allows a clean extraction of the strong coupling constant at low energies. We present a modification of the standard "contour improved" method based on a derivative expansion of the Adler function. The…

High Energy Physics - Phenomenology · Physics 2010-12-13 Gorazd Cvetic , Marcelo Loewe , Cristian Martinez , Cristian Valenzuela

We employ optimal renormalization group analysis to semi-leptonic $\tau$-decay polarization functions and extract the strange quark mass from their moments measured by the ALEPH and OPAL collaborations. The optimal renormalization group…

High Energy Physics - Phenomenology · Physics 2017-03-03 B. Ananthanarayan , Diganta Das

We have determined the strong coupling alpha-s from a comprehensive study of energy-energy correlations (EEC) and their asymmetry (AEEC) in hadronic decays of Z0 bosons collected by the SLD experiment at SLAC. The data were compared with…

High Energy Physics - Experiment · Physics 2009-09-25 K. Abe

This paper describes the trigger and offline reconstruction, identification and energy calibration algorithms for hadronic decays of tau leptons employed for the data collected from $pp$ collisions in 2012 with the ATLAS detector at the LHC…

High Energy Physics - Experiment · Physics 2015-07-16 ATLAS Collaboration

One of the main sources of theoretical uncertainty in the extraction of the strong coupling from hadronic tau decays stems from the renormalization-group improvement of the series. Perturbative series in QCD are divergent but are (most…

High Energy Physics - Phenomenology · Physics 2018-11-06 D. Boito , P. Masjuan , F. Oliani

We employ \textit{Levin-type sequence transformations} to accelerate the convergence of the perturbative fixed-order expansion of the QCD correction $\delta^{(0)}$ in terms of the strong coupling $\alpha_s$. The method efficiently resums…

High Energy Physics - Phenomenology · Physics 2026-01-21 Gauhar Abbas , Vartika Singh

Hadronically decaying tau leptons are of prime importance in numerous physics analyses in ATLAS. The spectrum of the possible applications of hadronically decaying tau leptons reaches from Standard Model measurements, including Higgs…

High Energy Physics - Experiment · Physics 2014-09-02 Zinonas Zinonos

We combine ALEPH and OPAL results for the spectral distributions measured in $\tau\to\pi^-\pi^0\nu_\tau$, $\tau\to 2\pi^-\pi^+\pi^0\nu_\tau$ and $\tau\to\pi^-3\pi^0\nu_\tau$ decays with (i) recent BaBar results for the analogous $\tau\to…

High Energy Physics - Phenomenology · Physics 2021-03-08 Diogo Boito , Maarten Golterman , Kim Maltman , Santiago Peris , Marcus V. Rodrigues , Wilder Schaaf

Three important QCD-related aspects of the $\tau$ and $\mu$ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value $\alpha_s(m_\tau^2) = 0.331 \pm 0.013$; the…

High Energy Physics - Phenomenology · Physics 2014-12-15 Antonio Pich

One of the largest theoretical uncertainties assigned to the strong coupling constant alpha_s as determined from hadronic tau decays stems from the differences in the results for Fixed Order Perturbation Theory (FOPT), Contour Improved…

High Energy Physics - Phenomenology · Physics 2009-06-11 Sven Menke

The calculation of perturbative corrections to the spectral moments observable in hadronic $\tau$ decays is reconsidered. The exact order-$\alpha_s^3$ results and the resummation procedure of Le~Diberder and Pich are compared with a partial…

High Energy Physics - Phenomenology · Physics 2009-10-28 Matthias Neubert

We analyze tau lepton decay observables, namely moments of the hadronic spectral density in the finite energy interval (0,M_\tau), within finite order perturbation theory including \alpha_s^4 corrections. The start of asymptotic growth of…

High Energy Physics - Phenomenology · Physics 2011-09-13 J. G. Koerner , F. Krajewski , A. A. Pivovarov

The current world-average of the strong coupling at the Z pole mass, $\alpha_s(m^2_{Z}) = 0.1181 \pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a…

High Energy Physics - Phenomenology · Physics 2016-06-29 David d'Enterria

The purely leptonic decays Ds -> tau nu and Ds -> mu nu are studied in a sample of four million hadronic Z decays collected with the ALEPH detector at the LEP e+e- collider from 1991 to 1995. The branching fractions are extracted from a…

High Energy Physics - Experiment · Physics 2012-08-27 ALEPH Collaboration

A new version of the so-called optimized perturbation (OPT), implementing consistently renormalization group properties, is used to calculate the nonperturbative ratio $F_\pi/\overline\Lambda$ of the pion decay constant and the basic QCD…

High Energy Physics - Phenomenology · Physics 2013-10-25 J-L. Kneur , A. Neveu

The total $\tau$ hadronic width can be accurately calculated using analyticity and the operator product expansion. The theoretical analysis of this observable is updated to include all available perturbative and non-perturbative…

High Energy Physics - Phenomenology · Physics 2009-10-28 A. Pich