Related papers: Recent results from e+ e- --> hadrons
I present a fairly detailed discussion of various contributions to the anomalous magnetic moment of the muon a_mu. I try to give an unbiased evaluation of the validity of the SM prediction for this quantity and to point out some delicate…
The state of the art concerning transverse-spin and transverse-momentum phenomena in hard hadronic reactions is reviewed. An account is given of single-spin and azimuthal asymmetries in semiinclusive deep inelastic scattering, e^+ e^-…
The important consequences of the recent results of the numerical evaluations of eighth and tenth order QED contributions to the anomalous magnetic moment of electron are commented. The correctness of the results of the numerical evaluation…
In view of the current 3 - 4 $\sigma$ deviation between theoretical and experimental values for the muon's anomalous magnetic moment, we review the ongoing efforts in constraining the hadronic light-by-light contribution to $a_\mu$ by using…
The most recent b-physics results from the OPAL experiment at LEP are reviewed. A measurement of semileptonic B meson decays to narrow orbitally-excited charm mesons is presented first, followed by a study of charm production in b-hadron…
We present preliminary BaBar measurements of hadronic cross sections in $e^+e^-$ annihilation using the radiative return technique. The cross sections for $e^+e^- \to p\bar{p} $, $ 3(\pi^+\pi^-)$, $ 2(\pi^+\pi^-)2\pi^0$, and $…
Events with tagged photons in the process of electron-positron annihilation into hadrons are considered. The initial state radiation is suggested to scan the hadronic cross section with the energy. QED radiative corrections are taken into…
We review the role of the anomalous magnetic moment of the muon a_\mu as a powerful probe of physics beyond the Standard Model (BSM), taking advantage of the final result of the Fermilab g-2 experiment and the recently updated Standard…
I present a new data driven update of the hadronic vacuum polarization effects for the muon and the electron $g-2$. For the leading order contributions I find $a_\mu^{\mathrm{had}(1)}=(686.99\pm 4.21)[687.19\pm 3.48]\times 10^{-10}$ based…
A summary is given of the present status of the theory and experiment of the anomalous magnetic moment of the muon. A difference between predicted and measured values is an indication of physics beyond the Standard Model. A new experimental…
The lowest order hadronic contribution to the $g-2$ factor of the muon is analyzed in the framework of the operator product expansion at short distances, and a QCD finite energy sum rule designed to quench the role of the $e^+ e^-$ data.…
The Born cross section and dressed cross section of $e^+e^-$ to $b\bar{b}$ and the total hadronic cross section in $e^+e^-$ annihilation in the bottomonium energy region are calculated based on the Rb values measured by the BaBar and Belle…
A coherent study of $e^{+}e^{-}$ annihilation into two ($\pi^{+}\pi^{-}$,$K^{+}K^{-}$) and three ($\pi^{+}\pi^{-}\pi^{0},\pi^{+}\pi^{-}\eta$) pseudoscalar meson production is carried out within the framework of resonance chiral theory in…
The past five years have brought significant new results on the muon magnetic anomaly, $a_\mu = (g_\mu - 2)/2$, and on the hadronic vacuum polarization (HVP) contribution dominating the uncertainty $\Delta a_\mu$. Serious tension has…
Some recent precision experiments in low energy muon physics are discussed. Spectroscopy on the muonium atom, the bound state of a positve muon and an electron, has provided precise tests of standard theory and yielded most precise values…
We calculate the leading isospin-violating and electromagnetic corrections for the decay tau --> pi^0 pi nu_tau at low energies. The corrections are small but relevant for the inclusion of tau decay data in the determination of hadronic…
A mathematical formalism for the analysis of correlations in multi-source events such as $W^+W^-$ production in $e^+e^-$ annihilations is presented. Various measures used in experimental searches for inter-$W$ correlations are reviewed.
We report about recent results obtained for the muon anomalous magnetic moment. Three-loop kernel functions have been computed to obtain the next-to-next-to-leading-order hadronic vacuum polarization contributions. The numerical result,…
In this paper it is shown that a recent formulation of the electron in terms of a Kerr-Newman type metric, exhibits a short range magnetic effect, as indeed has been observed at Cornell, and also an Aharonov-Bohm type of an effect.
Electron--positron annihilation into hadrons plus an energetic photon from initial-state radiation allows the hadronic cross-section to be measured over a wide range of energies at high luminosity meson factories. Weighted integrals over…