Related papers: Two-pion contribution to hadronic vacuum polarizat…
This work presents the results of a revised analysis of the low-energy (pion laboratory kinetic energy T(sub pi) < 100 MeV) pi+ p data using recently obtained electromagnetic corrections. The measurements are analyzed assuming extended…
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 study isospin-1 P-wave $\pi\pi$ scattering in lattice QCD with two flavours of O($a$) improved Wilson fermions. For pion masses ranging from $m_\pi=265$ MeV to $m_\pi=437$ MeV, we determine the energy spectrum in the centre-of-mass frame…
The two-pion low-energy contribution to the anomalous magnetic moment of the muon, $a_\mu\equiv(g-2)_\mu/2$, expres sed as an integral over the modulus squared of the pion electromagnetic form fac tor, brings a relatively large contribution…
We present a systematic study of the hadronic contributions to the muon anomalous magnetic moment within several infrared-improved AdS/QCD models. The models are constrained by the pion decay constant and the $\rho$-meson mass and are shown…
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…
The hadronic light-by-light contribution to the anomalous magnetic moment of the muon was recently analyzed in the framework of dispersion theory, providing a systematic formalism where all input quantities are expressed in terms of…
The spectral function of the charged pion form factor was extracted from two data sets. The difference between the two sets is based on the presence or absence of the recent measurement of the $\pi^+ \pi^-$ production by CMD3. Although the…
Isospin-breaking (IB) effects in the two-pion contribution to hadronic vacuum polarization (HVP) can be resonantly enhanced, if related to the interference of the $\rho(770)$ and $\omega(782)$ resonances. This particular IB contribution to…
We obtain reliable $\pi\pi$ scattering amplitudes consistent with experimental data, both at low and high energies, and fulfilling appropriate analyticity properties. We do this by first fitting experimental low energy ($s^{1/2}\leq1.42…
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…
I review the recent efforts to improve the precision of the prediction of the anomalous moment of the muon, in particular of the hadronic contribution of the vacuum polarization, which is the contribution with the largest uncertainty. Focus…
We present preliminary results of an improved pion-pion scattering dispersive analysis that includes: a refined treatment of inelasticities, the introduction of G-waves, the extension of Forward Dispersion Relations as constraints up to 1.6…
We construct a physically motivated model for the isospin-one non-strange vacuum polarization function Pi(Q^2) based on a spectral function given by vector-channel OPAL data from hadronic tau decays for energies below the tau mass and a…
We consider the subleading contributions of the hadronic vacuum polarization, involving the $\pi^0\gamma^*\gamma^*$ transition form factor, to the muon anomalous magnetic moment $g-2$. Various models for the form factor, based on hadronic…
Precise data on e^+e^- to hadrons have recently become available and are used to compute the lowest-order hadronic vacuum polarisation contribution to the muon magnetic anomaly through dispersion relations. This is the case for the dominant…
We revisit the isospin-breaking corrections relating the $e^+e^-$ hadronic cross-section and the tau decay spectral function, focusing on the di-pion channel, that gives the dominant contribution to the hadronic vacuum polarization piece of…
We use recently evaluated radiative and nonperturbative corrections to production of heavy quarks by a vector current to give very precise theoretical calculations of the high energy ($t^{1/2}\geq \sqrt{2}$ GeV) imaginary part of the photon…
We investigate restrictions on the hadronic contribution to the muon $(g-2)$ factor and to the pion electromagnetic formfactor from the analytical properties of the pion formfactor and the experimental data of the pion formfactor in the…
The Vector Pion form factor below 1 GeV is analyzed using experimental data on its modulus, the P-wave pion pion phase shifts and dispersion relation. It is found that causality is satisfied. Using dispersion relation, terms proportional to…