相关论文: On Constraints Between $\Delta\alpha_{\rm had}(M_Z…
The hadronic vacuum-polarization contribution to the muon anomalous magnetic moment a_{mu}(hadr) and to the value of the eleectromagnetic coupling constant at q^2 = M^2_z are determined more precisely in connection with a new more exact…
The discrepancy between the Standard Model theory and experimental measurement of the muon magnetic moment anomaly, $a_{\mu}=\left(g_{\mu}-2\right)/2$, is connected to precision electroweak (EW) predictions via their common dependence on…
I review recent evaluations of the hadronic contributions to the muon anomalous magnetic moment (g-2)_mu and to the effective fine structure constant alpha (M_Z). A new estimate for the hadronic shift delta_alpha hadronic = 0.027782 +/-…
This talk summarizes the recent development in the evaluation of the leading order hadronic contributions to the running of the QED fine structure constant \alpha(s), at $s=M_{\rm Z}^2$, and to the anomalous magnetic moments of the muon…
Recent evaluations of the hadronic vacuum polarization contributions to the effective fine-structure constant alpha_{em}(M_Z) are summarized and commented. A new update based on corrected CMD-2 data is presented. My new estimates are Delta…
Hadronic vacuum polarization (HVP) is not only a critical part of the Standard Model (SM) prediction for the anomalous magnetic moment of the muon $(g-2)_\mu$, but also a crucial ingredient for global fits to electroweak (EW) precision…
(Abridged) Many-multiplet (MM) method applied to three inhomogeneous samples of Keck/HIRES quasar absorption spectra gives a shift in the value of the fine-structure constant of Delta alpha/alpha = (-5.4+/-1.2) 10^{-6} in the redshift range…
The elliptic flow splitting $\Delta v_2$ between $\bar{u}$ and $u$ quarks as well as between $\pi^-$ and $\pi^+$ in midcentral Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV has been studied, based on the framework of an extended multiphase…
We review the determination of the QED coupling at the Z pole, which is a crucial parameter for electroweak theory. We include recent e+e- -> hadron data from Novosibirsk and Beijing to re-evaluate alpha (M_Z^2). We find 1/alpha (M_Z^2) =…
This talk summarizes the recent developments in the evaluation of the leading order hadronic contributions to the running of the QED fine structure constant $\alpha(s)$, at $s=M_{\rm Z}^2$, and to the anomalous magnetic moment of the muon…
We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the $Z$-boson mass. We include newest $e^+e^- \to$ hadrons cross-section data together…
Spatial and temporal variations in the electron-to-proton mass ratio, mu, and in the fine-structure constant, alpha, are predicted in non-Standard models aimed to explain the nature of dark energy. Among them the so-called chameleon-like…
Following updates in the compilation of $e^+e^-\rightarrow{\rm hadrons}$ data, this work presents re-evaluations of the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the electron ($a_e$), muon ($a_\mu$) and…
We reevaluate the dispersion integrals of the leading order hadronic contributions to the running of the QED fine structure constant alpha(s) at s=M_Z^2, and to the anomalous magnetic moments of the muon and the electron. Finite-energy QCD…
Sum rule constraints dominated by the independent high-scale input, alpha_s(M_Z), are shown to be satisfied by I=1 spectral data from hadronic tau decays, but violated by the pre-2005 electroproduction (EM) cross-section data.…
This work presents a complete re-evaluation of the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon, $a_{\mu}^{\rm had, \, VP}$ and the hadronic contributions to the effective QED coupling at the mass…
We update our Standard Model predictions for g-2 of the muon and for the hadronic contributions to the running of the QED coupling, Delta alpha_had^(5)(M_Z^2). Particular emphasis is put on recent changes in the hadronic contributions from…
We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the Z-boson mass. We include newest e+e- to hadrons cross-section data (among others)…
We recalculate the hadronic contribution to the effective electromagnetic coupling constant $\alpha(M^2_Z)$ using quasi-analytical approximations for the cross-section of $e^{+}e^{-} \to hadrons$ proposed earlier by one of the…
An update is described of a model independent method to determine the hadronic contribution to the QED running coupling at the Z-boson mass scale, $\Delta\alpha_{\text{HAD}}(M_{Z}^{2})$. The major source of uncertainty is from the…