Related papers: Hadronic vacuum polarization and vector-meson reso…
We revisit the isospin-breaking and electromagnetic corrections to the decay $\tau^-\to\pi^-\pi^0\nu_\tau$, which allow its use as input in the two-pion contribution to the (leading order) hadronic vacuum polarization part of the muon…
We report a measurement of the $e^+e^- \to \pi^+\pi^-\pi^0$ cross section in the energy range from 0.62 to 3.50 GeV using an initial-state radiation technique. We use an $e^+e^-$ data sample corresponding to 191 $\text{fb}^{-1}$ of…
The ratios among the leading-order (LO) hadronic vacuum polarization (HVP) contributions to the anomalous magnetic moments of electron, muon and tau-lepton, $a_{\ell=e,\mu \tau}^{HVP,LO}$, are computed using lattice QCD+QED simulations. The…
In a combined analysis of the experimental data on the coupled processes $\pi\pi\to\pi\pi,K\bar{K}$ in the channel with $I^GJ^{PC}=0^+0^{++}$, the various scenarios of these reactions (with different numbers of resonances) are considered.…
I present the calculation of the $\pi^+\gamma^\star\to\pi^+\pi^0$ transition amplitude from quantum chromodynamics performed by the Hadron Spectrum Collaboration. The amplitude is determined for a range of values of the photon virtuality…
The pion- and photon induced reactions for the final states $\gamma N$, $\pi N$, $2\pi N$, $\eta N$, and $\omega N$ are studied within a coupled-channel effective Lagrangian approach in the energy region from the pion threshold up to 2 GeV.…
The $e^+e^-\to K^+K^-$ cross section and charged-kaon electromagnetic form factor are measured in the $e^+e^-$ center-of-mass energy range ($E$) from 2.6 to 8.0 GeV using the initial-state radiation technique with an undetected photon. The…
BES II data for the channel J/Psi -> gamma (piplus-piminus-piplus-piminus) are analysed from a sample of 58M J/Psi hadronic interactions. They reveal further detail in the J^{PC} = 0^{-+} sector for the 4pi channel. A broad 0^{-+} ->…
The hadronic vacuum polarization correction to the $g$ factor of a bound electron is investigated theoretically. An effective hadronic Uehling potential obtained from measured cross sections of $e^- e^+$ annihilation into hadrons is…
The by now well-established scalar-isoscalar resonance $f_{0}(500)$ (the $\sigma$ meson) seems potentially relevant in the evaluation of thermodynamic quantities of a hadronic gas, since its mass is low. However, we recall that its…
We argue that the recent BESIII data on the cross section for the process $e^+e^- \to \chi_{c0} \, \omega$ in the center of mass energy range 4.21 - 4.42 GeV can be described by the contribution of the known charmonium-like resonance…
Results on the lowest-order hadronic vacuum polarization contribution to the muon magnetic anomaly are presented. They are based on the latest published experimental data used as input to the dispersion integral. Thus recent results on tau…
We propose a new method for the Coulomb wave function correction including the momentum resolution for charged hadron pairs and apply it to the precise data on $\pi^+\pi^-$ correlations obtained in $p + \mbox{Ta}$ reaction at 70 GeV/c. It…
Based on $e^{+}e^{-}$ collision data collected by the BESIII detector at the BEPCII collider at center-of-mass energies from 2.000 to 3.080 GeV, a partial-wave analysis is performed for the process $e^{+}e^{-} \to K^{+}K^{-}\pi^{0}$. The…
The predictions for transition form factors $\gamma^*\to \gamma f_2(1270)$ and $\gamma^*\to \gamma a_2(1320)$ and corresponding $e^+e^-\to \gamma^*\to f_2\gamma$ and $e^+e^-\to \gamma^*\to a_2\gamma$ cross sections are obtained for the…
The shift of atomic energy levels due to hadronic vacuum polarization is evaluated in a semiempirical way for hydrogenlike ions and for muonic hydrogen. A parametric hadronic polarization function obtained from experimental cross sections…
The QED hadronic vacuum polarization function plays an important role in the determination of precision electroweak observables and of the anomalous magnetic moment of the muon. These contributions have been computed from data, by means of…
The hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon, $a_{\mu}^{\rm had, VP}$ have been re-evaluated from the combination of $e^+e^-\rightarrow {\rm hadrons}$ cross section data. Focus has been placed…
We analyze a 37 pb$^{-1}$ data sample collected with the SND detector at the VEPP-2000 $e^+e^-$ collider in the center-of-mass energy range 1.05--2.00 GeV and present an updated measurement of the $e^+e^- \to \omega \pi^0 \to…
We have reevaluated the hadronic contribution to the anomalous magnetic moment of the muon (g-2) and to the running of the QED fine structure constant alpha(s) at s=M_Z**2. We incorporated new data from hadronic tau decays, recently…