Related papers: Data-based form factor corrections between the two…
We use an abelian model to study linear power corrections which arise from infrared renormalons and affect event shapes in $e^+e^-$ annihilation into hadrons. While previous studies explored power corrections in the two-jet region, in this…
The cross section of e^+e^- to pi^+pi^-pi^+pi^- has been measured by BABAR collaboration. We apply the theoretical cross section deduced from the extended VMD (VectorMeson Dominance) model to fit these experimental data. The relevant…
Hadronic decays of the $\tau$ lepton provide a clean environment to study hadron dynamics in an energy regime dominated by resonances, with the interesting information captured in the spectral functions. Recent results from ALEPH on…
We have measured the cross section $\sigma(e^+e^-\to \pi^+\pi^- \gamma)$ at an energy $W=m_\phi=1.02$ GeV with the KLOE detector at the electron-positron collider DA$\Phi$NE. From the dependence of the cross section on the invariant mass of…
A global fit to the data from different collaborations (CELLO, CLEO, BaBar) on the pion-photon transition form factor is carried out using light-cone sum rules. The analysis includes the next-to-leading QCD radiative corrections and the…
We analyze the hadronization structure of $\tau \to \eta \pi^- \pi^0 \nu_\tau$ decays. In the isospin limit only the vector current contributes to this process. We compute the relevant form factor within Resonance Chiral Theory, at leading…
We have measured the cross section $\sigma(e^+e^-\to\pi^+\pi^-\gamma)$ with the KLOE detector at DA$\Phi$NE, at an energy $W=M_\phi=1.02$ GeV. From the dependence of the cross section on $m(\pi^+\pi^-)=\sqrt{W^2-2WE_\gamma}$, where…
We report a high-statistics measurement of the branching fraction for tau^- --> pi^- pi^0 nu_tau and the invariant mass spectrum of the produced pi^- pi^0 system using 72.2 fb^-1 of data recorded with the Belle detector at the KEKB…
Employing our previous framework to treat non-perturbative effects self-consistently, including duality violations, we update the determination of the strong coupling, \alpha_s, using a modified version of the 1998 OPAL data, updated to…
The vector and scalar form factors relevant to the second-class current $\tau^-\to\pi^-\eta^{(\prime)}\nu_\tau$ processes are evaluated supplementing Chiral Perturbation Theory with the inclusion of resonances as explicit degrees of…
An improved description of four-pion production in electron-positron annihilation and in tau lepton decays is presented. The model amplitude is fitted to recent data from BaBar which cover a wide energy range and which were obtained…
A method to extract Wilson coefficients for semi-leptonic $b\rightarrow s$ transition and form factors for the hadronic process $B\rightarrow K^*\mu^+\mu^-$ is suggested. The method is based on data of angular distribution of the process…
We study consistently the pion's static observables and the elastic and \gamma*\gamma -> \pi^0 transition form factors within a light-front model. Consistency requires that all calculations are performed within a given model with the same…
In this work we explore the semileptonic $\tau$ decays into the axion-like particle ($a$)-meson final states within chiral effective field theory. The next-to-leading-order mixing matrix for the $\pi^0$-$\eta$-$\eta'$-$a$ system with the…
We use light-cone QCD sum rules to calculate the pion-photon transition form factor, taking into account radiative corrections up to the next-to-next-to-leading order of perturbation theory. We compare the obtained predictions with all…
It is well known that in every experiment involving charged particles there are individual photons emitted with small energy /omega and those with /omega < /omega_{0} will not be detected but are present in the data. The typical procedure…
When aiming at the percent precision in hadronic quantities calculated by means of lattice simulations, isospin breaking effects become relevant. These are of two kinds: up/down mass splitting and electromagnetic corrections. In order to…
Relying on the Hidden Local Symmetry (HLS) model equipped with a mechanism breaking the U(3)/SU(3)/SU(2) symmetries and generating a dynamical vector meson mixing, it has been shown that a global fit successfully describes the cross…
First correction to the high-energy asymptotics of the total $e^+e^-$ photoproduction cross section in the electric field of a heavy atom is obtained with the exact account of this field. The consideration is based on the use of the…
We present an improved Standard-Model (SM) prediction for the dilepton decay of the neutral pion. The loop amplitude is determined by the pion transition form factor for $\pi^0\to\gamma^*\gamma^*$, for which we employ a dispersive…