ar X iv : h ep - p h / 94 02 28 0 v 3 8 S ep 1 99 4 The Pion Form Factor . Where Does It Come From ?

ar X iv : h ep - p h / 02 09 22 4 v 1 1 9 Se p 20 02 1 Vector form factor of the pion : A model – independent approach ∗

We study a model–independent parameterization of the vector pion form factor that arises from the constraints of analyticity and unitarity. Our description should be suitable up to √ s ≃ 1.2 GeV and allows a model– independent determination of the mass of the ρ(770) resonance. We analyse the experimental data on τ − → π − π 0 ντ and e + e − → π + π − in this framework, and its consequences on t...

ar X iv : h ep - p h / 99 12 28 8 v 1 1 0 D ec 1 99 9 Lattice Calculations and Hadron Physics

ar X iv : h ep - p h / 97 05 42 3 v 1 2 6 M ay 1 99 7 The γ ∗ π 0 → γ form factor

The γπ → γ form factor is obtained within the Lagrangian quark model with separable interaction known to provide a good description of the pion observables at low energies. The pion-quarks vertex is chosen in a Gaussian form. The form factor obtained is close to the available experimental data and reaches smoothly the Brodsky-Lepage limit at Q ≈ 10 GeV.

ar X iv : h ep - l at / 9 71 10 28 v 1 1 5 N ov 1 99 7 1 First study of B → π semileptonic decay form factors using NRQCD

We present a quenched calculation of the form factors of the semileptonic weak decay B → πl¯ ν with O(1/mQ) NRQCD heavy quark and Wilson light quark on a 16 3 × 32 lattice at β = 5.8. The form factors are evaluated at six heavy quark masses, in the range of mQ ∼ 1.5 − 8 GeV. 1/mQ dependence of matrix elements are investigated and compared with HQET predictions. We observe clear signal for the f...

ar X iv : h ep - p h / 94 10 30 4 v 2 1 8 O ct 1 99 4 WU B 94 - 28 MESON - PHOTON TRANSITION FORM FACTORS

We report results on the π-γ transition form factor obtained within the hard scattering approach including transverse momentum effects and Sudakov corrections. The results clearly favor distribution amplitudes close to the asymp-totic form, ∼ x 1 x 2 , and disfavor distribution amplitudes which are strongly concentrated in the end-point regions. This observation is backed by information on the ...