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This paper presents a detailed account of evaluation of the electron anomalous magnetic moment a e which arises from the gauge-invariant set, called Set V, consisting of 6354 tenth-order Feynman diagrams without closed lepton loops. The latest value of the sum of Set V diagrams evaluated by the Monte-Carlo integration routine VEGAS is 8.726 (336)(α/π) 5 , which replaces the very preliminary value reported in 2012. Combining it with other 6318 tenth-order diagrams published previously we obtain 7.795 (336)(α/π) 5 as the complete mass-independent tenth-order term. Together with the improved value of the eighth-order term this leads to a e (theory) = 1 159 652 181.643 (25)(23)(16)(763) × 10 −12 , where first three uncertainties are from the eighth-order term, tenth-order term, and hadronic and elecroweak terms. The fourth and largest uncertainty is from α −1 = 137.035 999 049 (90), the fine-structure constant derived from the rubidium recoil measurement. Thus, a e (experiment) − a e (theory) = −0.91 (0.82) × 10 −12 .Assuming the validity of the standard model, we obtain the fine-structure constant α −1 (a e ) = 137.035 999 1570 (29)(27)(18)(331), where uncertainties are from the eighth-order term, tenthorder term, hadronic and electroweak terms, and the measurement of a e . This is the most precise value of α available at present and provides a stringent constraint on possible theories beyond the standard model.

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“…The mass-dependent terms A 2 and A 3 of the fourth and sixth orders are known [24][25][26][27][28][29], A …”

Section: )mentioning

confidence: 99%

Tenth-order electron anomalous magnetic moment: Contribution of diagrams without closed lepton loops

et al. 2015

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“…However, as this region contributes more than 80 % to the total HVP, improvements which can follow from the broken HLS model are certainly valuable. 3 The global simultaneous fit of the data corresponding to the channels quoted above allows to reconstruct the various cross sections σ H i (s) taking automatically into account the physics correlations inside the set H ≡ {H i } of possible final states and decay processes. The fit parameter values and the parameter error covariance matrix summarize optimally the full knowledge of H. This has two important consequences:…”

Section: N} To the Annihilation Cross Sections σ (E + E − → H I )mentioning

confidence: 99%

“…The Hidden Local Symmetry (HLS) ansatz [14,15] is an extension of the ChPT non-linear sigma model to a nonlinear chiral Lagrangian based on the symmetry pattern G global /H local , where G = SU(3) L ⊗ SU (3) R is the chiral group of QCD and H = SU (3) V is the vector subgroup. The hidden local SU(3) V requires the vector meson fields, represented by the SU(3) matrix field V μ , to be gauge fields.…”

Section: The General Context Of the Hls Modelmentioning

confidence: 99%

“…The predicted value is the sum a e-mail: benayoun@in2p3.fr of several contributions and the most prominent ones are already derived from the Standard Model with very high accuracies. The QED contribution is thus estimated with an accuracy of a few 10 −12 [1][2][3] and the precision of the electroweak contribution is now of order 10 −11 [4]. The lightby-light contribution to a μ is currently known with an accepted accuracy of 2.6 × 10 −10 [5].…”

Section: Introductionmentioning

confidence: 99%

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An update of the HLS estimate of the muon g−2

et al. 2013

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A global fit of parameters allows us to pin down the Hidden Local Symmetry (HLS) effective Lagrangian, which we apply for the prediction of the leading hadronic vacuum polarization contribution to the muon g − 2. The latter is dominated by the annihilation channel e + e − → π + π − , for which data are available by scan (CMD-2 & SND) and ISR (KLOE-2008, KLOE-2010 experiments. It is well known that the different data sets are not in satisfactory agreement. In fact it is possible to fix the model parameters without using the π + π − data, by using instead the dipion spectra measured in the τ -decays together with experimental spectra for the π 0 γ , ηγ , π + π − π 0 , K + K − , K 0 K 0 final states, supplemented by specific meson decay properties. Among these, the accepted decay width for ρ 0 → e + e − and the partial widths and phase information for the ω/φ → π + π − transitions, are considered. It is then shown that, relying on this global data set, the HLS model, appropriately broken, allows to predict accurately the pion form factor below 1.05 GeV. It is shown that the data samples provided by CMD-2, SND and KLOE-2010 behave consistently with each other and with the other considered data. Consistency problems with the KLOE-2008 and BaBar data samples are substantiated. "All data" global fits are investigated by applying reweighting the conflicting data sets. Constraining to our best fit, the broken HLS model yields a th μ = (11 659 169.55 + +1.26 −0.59 φ + +0.00 −2.00 τ ± 5.21 th ) 10 −10 associated with a very good global fit probability. Correspondingly, we find that a μ = a exp μ − a th μ exhibits a significance ranging between 4.7 and 4.9σ .

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“…Other limits on the MM and EDM of the τ-lepton are reported in Refs. [7,[28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

Section: Introductionmentioning

confidence: 99%

Model-independent sensitivity estimates for the electromagnetic dipole moments of the τ -lepton at the CLIC

et al. 2018

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We establish model-independent sensitivity on the anomalous magnetic and electric dipole moments of the τ-lepton using the two-photon processes γγ → τ þ τ − and γγ → τ þ τ − γ. We use L ¼ 10, 50, 100, 300, 500, 1000, 1500, 2000, 3000 fb −1 data collected with the future e þ e − linear collider such as the CLIC at ffiffi ffi s p ¼ 380, 1500, 3000 GeV, and we consider systematic uncertainties of δ sys ¼ 0%, 3%, 5%. We obtain sensitivity estimates at 95% C.L. on the anomalous dipole moments to the τ-lepton −0.00015 ≤ã τ ≤ 0.00017 and jd τ ðecmÞj ¼ 9.040 × 10 −19 that may be achievable in future experiments. Our results show that the processes under consideration are very promising for probing the dipole moments of the τ-lepton at the future e þ e − linear collider at the γγ mode.

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Precise mass-dependent QED contributions to leptonicg−2at orderα2andα3

Cited by 89 publications

References 71 publications

Tenth-order electron anomalous magnetic moment: Contribution of diagrams without closed lepton loops

Tenth-order electron anomalous magnetic moment: Contribution of diagrams without closed lepton loops

An update of the HLS estimate of the muon g−2

Model-independent sensitivity estimates for the electromagnetic dipole moments of the τ -lepton at the CLIC

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