相关论文: $\pi NN$ and Pseudoscalar Form Factors from Lattic…
We extend recently developed methods used for determining the electromagnetic charge radius and $a_\mu^{\pi\pi}$ to obtain a determination of the electromagnetic form factor of the pion, $F_\pi^V(t)$, in several significant kinematical…
We suggest to probe the pion light-cone distribution amplitude, applying a dispersion relation for the pion electromagnetic form factor. Instead of the standard dispersion relation, we use the equation between the spacelike form factor…
We compute the electromagnetic form factors of the proton and neutron using lattice QCD with $N_f = 2 + 1 + 1$ twisted mass clover-improved fermions and quark masses tuned to their physical values. Three ensembles with lattice spacings of…
An interesting connection between the nucleon weak axial-vector second class current form factor $g_{T}(q^{2})$ present in the matrix element $< {p} | A_{\pi ^{+}}^{\mu}| {n} >$ and the $\Delta N\gamma$ form factors $G_{M}^{\ast}(q^{2})$…
We present preliminary results on the axial form factor $G_A(Q^2)$ and the induced pseudoscalar form factor $G_P(Q^2)$ of the nucleon. A systematic analysis of the excited-state contributions to form factors is performed on the CLS ensemble…
We present the current status of our lattice calculation of the electromagnetic form factor of the pion with two flavours of non-perturbatively O(a)-improved Wilson fermions. Using twisted boundary conditions and stochastic sources we…
The holographic QCD prediction for the pion distribution amplitude (DA) $\phi_{hol}(u)$ is used to compute the pion spacelike electromagnetic form factor $F_{\pi}(Q^2)$ within the QCD light-cone sum rule method. In calculations the pion's…
We present the first calculation of the pion electromagnetic form factor at physical light quark masses. This form factor parameterises the deviations from the behaviour of a point-like particle when a photon hits the pion. These deviations…
We perform the first global QCD analysis of parton distribution functions (PDFs) in the pion, with lattice-QCD data on gluonic pseudo--Ioffe-time distributions fitted simultaneously with experimental Drell-Yan and leading neutron…
We discuss the onset of the dominance of the Glauber-Gribov-Landshoff (GGL) component of pQCD hard two-gluon (2G) exchange contribution to hard elastic $\pi\pi$ scattering at moderate energies . Such a hard $\pi\pi$ scattering could via…
We present lattice results for the vector and scalar form factors of the semileptonic decays D -> \pi \ell \nu_ell and D -> K \ell \nu_\ell in the physical range of values of squared four momentum transfer q^2, obtained with N_f=2 maximally…
We calculate electric and magnetic form factors of protons and neutrons in quenched Monte Carlo lattice QCD on a $16^3\times 24$ lattice at $\beta = 6.0$ using Wilson fermions. We employ a method which characterizes one of the nucleon…
The form factors of the semileptonic $B\to \pi\pi\ell\bar\nu$ decay are calculated from QCD light-cone sum rules with the distribution amplitudes of dipion states. This method is valid in the kinematical region, where the hadronic dipion…
We present a recent calculation of the gravitational form factors (GFFs) of proton using the light-front quark-diquark model constructed by the soft-wall AdS/QCD. The four GFFs $~A(Q^2)$ , $B(Q^2)$ , $C(Q^2)$ and $\bar{C}(Q^2)$ are…
Effects of non-resonant photoproductions arising from two different $\pi NN$ couplings are investigated in the $\gamma N\to\pi\pi N$ reaction. We find that the pseudoscalar (PS) $\pi NN$ coupling is generally preferable to the pseudovector…
Results are presented on the neutron electric dipole moment using an ensemble of $N_f=2+1+1$ twisted mass clover-improved fermions with lattice spacing of $a\simeq 0.08$ fm and physical pion mass ($m_\pi\simeq 139$ MeV). The approach…
We report on our computation of the pion transition form factor ${\cal F}_{P\rightarrow \gamma^*\gamma^*}$ from twisted mass lattice QCD in order to determine the numerically dominant light pseudoscalar pole contribution in the hadronic…
A symmetry-preserving analysis of strong interaction quantum field equations is used to complete a unified treatment of pion, kaon, nucleon electromagnetic and gravitational form factors. Findings include a demonstration that the pion…
In this article, we calculate the scalar form-factor of the proton in the framework of the light-cone QCD sum rules approach with the three valence quark light-cone distribution amplitudes up to twist-6, and observe the scalar form-factor…
We study the topological susceptibility, chi, in two flavour lattice QCD. We find clear evidence for the expected suppression of chi at small quark mass. The estimate of the pion decay constant, f_pi = 105 +/-5 +18/-10 MeV, is consistent…