Reevaluation of the hadronic contributions to the muon g−2 and to $\alpha (M^{2}_{Z})$

By M. Davier, Andreas Hoecker, Bogdan Malaescu, Zhiqing Zhang. 2010

692 citations recorded by the source corpus.

We reevaluate the hadronic contributions to the muon magnetic anomaly, and to the running of the electromagnetic coupling constant at the Z-boson mass. We include new π+π− cross-section data from KLOE, all available multi-hadron data from BABAR, a reestimation of missing low-energy contributions using results on cross sections and process dynamics from BABAR, a reevaluation of all experimental contributions using the software package HVPTools together with a reanalysis of inter-experiment and inter-channel correlations, and a reevaluation of the continuum contributions from perturbative QCD at four loops. These improvements lead to a decrease in the hadronic contributions with respect to earlier evaluations. For the muon g−2 we find lowest-order hadronic contributions of (692.3±4.2)⋅10−10 and (701.5±4.7)⋅10−10 for the e+e−-based and τ-based analyses, respectively, and full Standard Model predictions that differ by 3.6σ and 2.4σ from the experimental value. For the e+e−-based five-quark hadronic contribution to $\alpha(M_{Z}^{2})$ we find $\varDelta \alpha_{\mathrm{had}}^{(5)}(M_{Z}^{2}) =(274.9\pm1.0)\cdot10^{-4}$. The reduced electromagnetic coupling strength at MZ leads to an increase by 12 GeV in the central value of the Higgs boson mass obtained by the standard Gfitter fit to electroweak precision data.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/746aff1d8285239412c9eed2983a8b73bf7936e1

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Nuclear and High Energy Physics

Citations in the corpus

Leading hadronic contribution to the muon magnetic moment from lattice QCD (2020, methodology): “It is worth pointing out that hadronic τ decays can be used, in principle, to provide an independent measurement of the spectral function in this important low-energy region, as first proposed in [101] and updated in [102–104].”
An update of the HLS estimate of the muon g−2 (2012, methodology): “18 illustrates that the global fit approach allows for a gain in the significance for aμ of about 1σ or more compared to the traditional methods based on numerical integration of the experimental cross sections [6–9].”
Reconsidering the one leptoquark solution: flavor anomalies and neutrino mass (2017, background): “We require that the leptoquark contribution account for the measured anomaly, and thus that aμ = (287± 80) · 10−11 [92].”
Revisiting the one leptoquark solution to the R(D(∗)) anomalies and its phenomenological implications (2016, background): “-scale scalar leptoquark ˚transforming as (3;1; 1 3 ) under the SM gauge group, and shown that the anomalies observed in B !D( )˝, B !K‘ +‘ [62], as well as the anomalous magnetic moment of muon [63] can be explained in a natural way, while constraints from other precision measurements in the avor s”
A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector (2012, background): “A further ⇠ 3 hint for physics beyond the SM, without such Higgs implications, is the deviation of the measured magnetic anomalous moment of the muon from its SM prediction [187].”