Related papers: Meson Transition Form Factors From A QCD Model Fie…
The quark-level linear sigma model is employed to compute a variety of electromagnetic and weak observables of light mesons, including pion and kaon form factors and charge radii, charged-pion polarizabilities, semileptonic weak $K_{\ell3}$…
We consider a model with $\rho\pi\pi$, $\rho KK$, and gauge-invariant $\rho\gamma$ couplings and obtain the pion form factor $F_\pi$ at timelike momentum transfers by resummation of pion and kaon loops. We use a dispersion representation…
Light-cone QCD sum rules to leading order in QCD are used to investigate the tensor form factors of the $\Sigma-\Sigma$, $\Xi-\Xi$ and $ \Sigma-\Lambda$ transitions in the range $1 GeV^2 \leq Q^2 \leq 10 GeV^2$. The DAs of $\Sigma$, $\Xi$…
Measurements and theoretical calculations of meson form factors are essential for our understanding of internal hadron structure and QCD, the dynamics that bind the quarks in hadrons. The pion electromagnetic form factor has been measured…
I review the QCD sum rules calculations of the form factors governing the semileptonic decays of charmed and beauty mesons. In particular, I discuss the predicted dependence of the various form factors on $q^2$ and how it can be obtained…
We scrutinize recent findings on the charged-pion elastic form factor and the form factors entering in neutral-meson-to-photons transition amplitudes within the framework of QCD sum rules.
We propose an interpolating formula for the amplitude induced by the axial anomaly, concentrating on the $\pi^0\gamma^{\ast}\gamma^{\ast}$ transition form factor. The QCD corrections to this amplitude are generally described by two major…
We calculate the form factors for the baryon number violation processes of a heavy-flavor baryon decaying into a pseudoscalar meson and a lepton. In the framework of the Standard Model effective field theory, the leptoquark operators at the…
We calculate the kaon semileptonic form factors in lattice QCD with three flavors of dynamical overlap quarks. Gauge ensembles are generated at pion masses as low as 290 MeV and at a strange quark mass near its physical value. We precisely…
The form factors of the light pseudoscalar mesons are investigated in a dispersive formalism based on hadronic unitarity, analyticity and the OPE expansion of the QCD Green functions. We propose generalizations of the original mathematical…
We discuss the evaluation of the transition form factor (TFF) $F^{\gamma*\gamma\pi^0}(Q^2)$ by means of QCD theory and by state-space reconstruction from topological data analysis. We first calculate this quantity in terms of quark-gluon…
Quark model results for the $B\to \pi,\rho$ decays are analysed, making use of the dispersion formulation of the model: The form factors at $q^2>0$ are expressed as relativistic invariant double spectral representation over invariant masses…
The analysis of the $\pi\gamma$ transition form factor provides severe constraints on the pion's wave function. This information is used to examine charmonium decays into two pions critically. It will be argued that the standard…
The transition gamma*(q_1)gamma*(q_2) -> \pi0(p) is studied within the QCD sum rule framework. As a first step, we analyze the kinematic situation when both photon virtualities are spacelike and large. We construct a QCD sum rule for…
We analyse the pion electromagnetic, charged-current, and $\pi\gamma$ transition form factors at timelike momentum transfers $q$, $q^2=s\le 1.4$ GeV$^2$, using a dispersion approach. We discuss in detail the propagator matrix of the…
The low $Q^2$ slopes of the the transition form factors provide a unique method to measure the sizes of the neutral pseudo-scalar mesons, since they do not have electromagnetic form factors. From the slope one obtains the "axial transition…
Taking into account only the quark part of the energy-momentum tensor, the gravitational form-factors of the $ \pi $ and $ K $ mesons are calculated within the light-cone sum rules method using the distribution amplitudes of these…
We study the form factors for a heavy meson into the S-wave $K\pi/\pi\pi$ system with an invariant mass below 1~GeV. The mesonic final state interactions are described in terms of the scalar form factors, which are obtained from unitarized…
We calculate the omega --> pi0 gamma* and phi --> pi0 gamma* electromagnetic transition form factors based on dispersion theory, relying solely on a previous dispersive analysis of the corresponding three-pion decays and the pion vector…
We analyse pionic couplings of heavy mesons combining PCAC with the dispersion quark model to calculate the relevant transition form factors. Ground states and radial excitations are considered. For the ground state coupling constants the…