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Taking into account the two-gluon condensate contributions, the transition form factors enrolled to the low energy effective Hamiltonian describing the semileptonic [formula] decay channel are calculated within three-point QCD sum rules. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The decay B→γℓνℓ receives a numerically large soft-overlap contribution which is formally next-to-leading order in the expansion in the inverse photon energy, 1/Eγ. We point out that this contribution can be calculated with little model-dependence making use of dispersion relations and duality, in full analogy with the similar contribution to the γγ*→π transition form factor. This result strengthens the case for the utility of the B→γℓνℓ decay for constraining the B-meson distribution amplitude and determining its most important parameter, the inverse moment λB. [ABSTRACT FROM AUTHOR]

We present the results of our recent analysis of the meson-photon transition form factors FPγ(Q2) for the pseudoscalar mesons P = π0,η,η′,ηc, using the local-duality version of QCD sum rules. [ABSTRACT FROM AUTHOR]

Form factors are important non-perturbative properties of hadrons. They give information about the internal structure of the hadrons. In this work, iso-vector axial-vector and iso-vector tensor form factors of the nucleon and the iso-vector axial-vector Δ → N transition form factor calculations in QCD Sum Rules are presented. [ABSTRACT FROM AUTHOR]

We extract constraints on the pion distribution amplitude from available data on the pionphoton transition form factor in the framework of light-cone sum rules. A pronounced discrepancy (2.7 - 3)σ between the Gegenbauer expansion coefficients extracted from the CELLO, CLEO, and Belle experimental data relative to those from BaBar is found. Predictions for the pion-photon transition form factor are presented by employing a pion distribution amplitude obtained long ago from QCD sum rules with nonlocal condensates. These predictions comply with the Belle data but disagree with those of BaBar beyond 9 GeV2. [ABSTRACT FROM AUTHOR]

The recent BaBar measurements of the γγ*→π0 transition form factor show spectacular deviation from perturbative QCD prediction for large space-like Q2 up to 34GeV2. In this talk, I would like to discuss a recent work on the chiral anomaly effects in the γγ*→π0 transition form factor F(Q2) at large momentum squared Q2. Using PCAC and the Adler-Bell-Jackiw chiral anomaly triangle graph, we find that, F(Q2) at large Q2 behaves as (m2Q2)×(ln(Q2/m2))2 and is in striking agreement with the BaBar data with m = 135MeV which also reproduces very well the CLEO data at lower Q2. The new Belle measurements could also be fitted with m = 120MeV. [ABSTRACT FROM AUTHOR]