Determination of the QCD coupling from ALEPH<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>τ</mml:mi></mml:math>decay data

Pich, Antonio; Rodríguez-Sánchez, Antonio

doi:10.1103/physrevd.94.034027

Cited by 110 publications

(353 citation statements)

References 66 publications

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“…In these figures we have taken Q 2 = −M 2 τ and the strong coupling constant is taken from direct measurements at the Z peak, α s (M 2 Z ) = 0.1197 ± 0.0028 [1]. This is evolved using a four-loop β function using the package [46,47] to the τ mass scale which yields α s (M 2 τ ) = 0.3298 ± 0.0118, and is in excellent agreement with the latest determination from τ -decay in [48]. The figures clearly show that the renormalization group improved series based on the optimal renormalization group has substantially less scale dependence than the unsummed series.…”

Section: Closed Form Sum Of Rg-accessible Logarithmssupporting

confidence: 56%

Optimal renormalization and the extraction of the strange quark mass from moments of the τ -decay spectral function

Ananthanarayan

Das

2016

Phys. Rev. D

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We introduce an optimal renormalization group analysis pertinent to the analysis of polarization functions associated with the s-quark mass relevant in τ -decay. The technique is based on the renormalization group invariance constraints which lead to closed form summation of all the leading and next-to-leading logarithms at each order in perturbation theory. The new perturbation series exhibits reduced sensitivity to the renormalization scale and improved behavior in the complex plane along the integration contour. Using improved experimental and theory inputs, we have extracted the value of the strange quark mass ms(2GeV) = 106.70 ± 9.36 MeV and ms(2GeV) = 74.47 ± 7.77 MeV from presently available ALEPH and OPAL data respectively. These determinations are in agreement with the determinations in other phenomenological methods and from the lattice.

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Section: Closed Form Sum Of Rg-accessible Logarithmssupporting

confidence: 56%

Optimal renormalization and the extraction of the strange quark mass from moments of the τ -decay spectral function

Ananthanarayan

Das

2016

Phys. Rev. D

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“…The actual uncertainties are much larger than the very naive fit errors shown in the table, since they totally ignore the strong instabilities appearing as soon as one moves from the selected pointŝ 0 = 1.55 GeV to increase by a factor of three the error quoted in Table 2. 1 As the fit quality improves with growing values of λ V , the fitted central values of α s (m 2 τ ) approach also the much more solid determinations quoted in Table 1.…”

mentioning

confidence: 57%

“…1 with a very comprehensive analysis of the most recent experimental data. The τ decay width is very sensitive to α s and provides a rigorous determination of the QCD coupling at the τ mass scale.…”

Section: Introductionmentioning

confidence: 99%

Updated determination of αs(mτ2) from τ decays

Pich

Rodríguez-Sánchez

2016

Mod. Phys. Lett. A

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Using the most recent release of the ALEPH τ decay data, we present a very detailed phenomenological update of the αs(m 2 τ ) determination. We have exploited the sensitivity to the strong coupling in many different ways, exploring several complementary methodologies. All determinations turn out to be in excellent agreement, allowing us to extract a very reliable value of the strong coupling. We find αZ ) = 0.1197 ± 0.0014. We critically revise previous work, and point out the problems flawing some recent analyses which claim slightly smaller values.

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“…As the result of this the error on the α s quoted in the most recent Particle Data Group (PDG) Review update has increased for the first time in many years: α s (M Z ) = 0.1181 (16) [5]. This should be compared to the 2013 PDG value, α s (M Z ) = 0.1185 (6). Lattice QCD offers the possibility to determine the strong coupling constant at relatively low energy scales.…”

Section: Introductionmentioning

confidence: 99%

“…So far the only non-lattice method that offers a low energy determination of α s is the analysis of the τ decay but there are large systematic uncertainties due to different ways of organizing the perturbative expansion in this method (see Ref. [6] for a recent work on this topic and references therein). For certain applications it is important to have the running of the coupling constant at low energy scales.…”

Section: Introductionmentioning

confidence: 99%

Quark masses and strong coupling constant in2+1flavor QCD

Maezawa

Petreczky

2016

Phys. Rev. D

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We present a determination of the strange, charm and bottom quark masses as well as the strong coupling constant in 2+1-flavor lattice QCD simulations using Highly Improved Staggered Quark action. The ratios of the charm quark mass to the strange quark mass and the bottom quark mass to the charm quark mass are obtained from the meson masses calculated on the lattice and found to be m c /m s = 11.877(91) and m b /m c = 4.528(57) in the continuum limit. We also determine the strong coupling constant and the charm quark mass using the moments of pseudoscalar charmonium correlators: α s (µ = m c ) = 0.3697(85) and m c (µ = m c ) = 1.267(12) GeV. Our result for α s corresponds to the determination of the strong coupling constant at the lowest energy scale so far and is translated to the value α s (µ = M Z , n f = 5) = 0.11622(84).

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Determination of the QCD coupling from ALEPHτdecay data

Cited by 110 publications

References 66 publications

Optimal renormalization and the extraction of the strange quark mass from moments of the τ -decay spectral function

Optimal renormalization and the extraction of the strange quark mass from moments of the τ -decay spectral function

Updated determination of αs(mτ2) from τ decays

Quark masses and strong coupling constant in2+1flavor QCD

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