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Related papers: Strong coupling at the $\tau$-mass scale from an i…

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Using the most recent release of the ALEPH $\tau$ decay data, we present a very detailed phenomenological update of the $\alpha_s(m_\tau^2)$ determination. We have exploited the sensitivity to the strong coupling in many different ways,…

High Energy Physics - Phenomenology · Physics 2016-10-12 Antonio Pich , Antonio Rodríguez Sánchez

We demonstrate the feasibility of determining the strong coupling constant, $\alpha_s$, from the inclusive semileptonic decay width of $B$ mesons. We express the semileptonic $B$ decay width as a function of $\alpha_s(5\mathrm{\,GeV})$, the…

High Energy Physics - Phenomenology · Physics 2025-10-07 Yuzhi Che , Long Chen , Jinfei Wu , Xinchou Lou , Xiang Chen , Xin Guan , Yan-Qing Ma , Manqi Ruan

The current phenomenological determinations of $\alpha_s(M_\tau)$ and $\alpha_s(M_Z)$ are shown to be only marginally consistent with the QCD evolution of the strong coupling constant between $M_Z$ and $M_\tau$. This motivates a revised…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. G. Steele , V. Elias

We present a new QCD sum rule with high sensitivity to the continuum regions of charm and bottom quark pair production. Combining this sum rule with existing ones yields very stable results for the MS-bar quark masses, m_c(m_c) and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jens Erler , Mingxing Luo

The strong coupling constant ($\alpha_{S}$) is a fundamental parameter of quantum chromodynamics (QCD), the theory of the strong force. Some of the earliest precise constraints on $\alpha_{S}$ came from measurements of event shape…

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 apply the Euler transformation to accelerate the convergence of the QCD perturbative series with the aim to determine the strong coupling $\alpha_s$ in terms of the total $\tau$-decay rate $r_\tau$. The variation of the result with the…

High Energy Physics - Phenomenology · Physics 2024-01-31 K. Schilcher , C. Sebu , H. Spiesberger

The (non-strange) vector and axial-vector spectral functions extracted from $\tau $-decay by the ALEPH collaboration are confronted with QCD in the framework of a Finite Energy QCD sum rule (FESR) involving a polynomial kernel tuned to…

High Energy Physics - Phenomenology · Physics 2009-11-06 C. A. Dominguez , N. F. Nasrallah , K. Schilcher

The finite energy sum rule extraction of the strong coupling {\alpha}_s from hadronic {\tau} decay data provides one of its most precise experimental determinations. As precision improves, small non-perturbative effects become increasingly…

High Energy Physics - Lattice · Physics 2011-11-23 Diogo Boito , Oscar Catà , Maarten Golterman , Matthias Jamin , Kim Maltman , James Osborne , Santiago Peris

Hadronic $\tau$ decays provide a clean laboratory for the precise study of quantum chromodynamics (QCD). Observables based on the spectral functions of hadronic $\tau$ decays can be related to QCD quark-level calculations to determine…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michel Davier , Andreas Hoecker , Zhiqing Zhang

We obtain a determination of the strong coupling alpha_s in quantum chromodynamics, by comparing perturbative calculations for the short-distance part of the static energy with lattice computations. Our result reads…

High Energy Physics - Phenomenology · Physics 2012-11-21 Xavier Garcia i Tormo

We determine elastic and coupled-channel amplitudes for isospin-1 meson-meson scattering in $P$-wave, by calculating correlation functions using lattice QCD with light quark masses such that $m_\pi = 236$ MeV in a cubic volume of $\sim (4…

High Energy Physics - Phenomenology · Physics 2015-11-11 David J. Wilson , Raul A. Briceno , Jozef J. Dudek , Robert G. Edwards , Christopher E. Thomas

The QCD vacuum condensates in the Operator Product Expansion are extracted from the final ALEPH data on vector and axial-vector spectral functions from $\tau$-decay. Weighted Finite Energy Sum Rules are employed in the framework of both…

High Energy Physics - Phenomenology · Physics 2010-10-27 C. A. Dominguez , K. Schilcher

We perform a combined analysis of $\tau\to K\pi \nu_\tau$ decay and $\pi K$ scattering with constraints from $K_{\ell3}$ data using a $N/D$ approach that fulfills requirements from unitarity and analyticity. We obtain a good fit of the…

High Energy Physics - Phenomenology · Physics 2015-06-17 Veronique Bernard

Comparing perturbative calculations with a lattice computation of the static energy in quantum chromodynamics at short distances, we obtain a determination of the strong coupling alpha_s. Our determination is performed at a scale of around…

High Energy Physics - Phenomenology · Physics 2012-08-27 Xavier Garcia i Tormo

We present a new determination of the strong coupling constant $\alpha_s$ from a global QCD analysis CT25 of parton distribution functions (PDFs) that incorporates high-precision experimental measurements from the Run-2 of the Large Hadron…

High Energy Physics - Phenomenology · Physics 2026-03-18 Alim Ablat , Sayipjamal Dulat , Marco Guzzi , Joey Huston , Kirtimaan Mohan , Pavel Nadolsky , Dan Stump , C. -P. Yuan

Employing our previous framework to treat non-perturbative effects self-consistently, including duality violations, we update the determination of the strong coupling, \alpha_s, using a modified version of the 1998 OPAL data, updated to…

High Energy Physics - Phenomenology · Physics 2013-05-30 Diogo Boito , Maarten Golterman , Matthias Jamin , Andisheh Mahdavi , Kim Maltman , James Osborne , Santiago Peris

Being a determination at low energies, the analysis of hadronic tau decay data provides a rather precise determination of the strong coupling alpha_s after evolving the result to M_Z. At such a level of precision, even small…

High Energy Physics - Phenomenology · Physics 2015-06-03 D. Boito , O. Cata , M. Golterman , M. Jamin , K. Maltman , J. Osborne , S. Peris

We review the current status of the determination of the strong coupling from tau decay. Using the most recent release of the ALEPH data, a very comprehensive phenomenological analysis has been performed, exploring all strategies previously…

High Energy Physics - Phenomenology · Physics 2018-11-27 Antonio Pich

We extract the strong coupling constant $\alpha_s(m_\tau^2)$ from the semileptonic $\tau$ decay width taking into account resummation effects from the running of the strong coupling constant. In the $\overline{\rm MS}$ scheme the result…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Groote , J. G. Körner , A. A. Pivovarov