相关论文: Pion electromagnetic form factor in the Covariant …
A new formula for the pion form factor F_pi is proposed which takes into account the pseudoscalar meson loops and the mixing among rho(770), rho(1450), and rho(1700). The expression possesses correct analytical properties and can be used in…
We present a procedure to derive a covariant electromagnetic current operator for a system made up by two scalars constituents. Using different wave functions we fitted their parameters to the experimental data of the pion form factor,…
Results of the Spectral Quark Model for the gravitational, electromagnetic, and transition form factors of the pion are discussed. In this model both the parton distribution amplitude and the parton distribution function are flat, in…
We study the electromagnetic form factors of the lowest-lying singly heavy baryons with spin 1/2 within the framework of the chiral quark-soliton model, focusing on the comparison with recent lattice data. To compare the present results…
We consider the pion structure in the region of low and moderately high momentum transfers: at low $Q^2$, the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, $Q^2=10\div25\;GeV^2$, the…
Using a holographic dual model of QCD, we compute the pion electromagnetic form factor F_pi(Q^2) in the spacelike momentum transfer region, as well as pion couplings to vector mesons g_rho^(n) pi pi. Spontaneous and explicit chiral symmetry…
The two gravitational form factors of the pion, $A^{\pi}(t)$ and $D^{\pi}(t)$, are computed as functions of the momentum transfer squared $t$ in the kinematic region $0\leq -t< 2~\text{GeV}^2$ on a lattice QCD ensemble with quark masses…
We discuss a constraint of conformal symmetry in the analysis of the pion form factor. The usual power-law behavior of the form factor obtained in the perturbative QCD analysis can also be attained by taking negligible quark masses in the…
The asymptotics of pion charge form factor is obtained in the framework of relativistic Hamiltonian dynamics for the infinite value limit of momentum transfer and zero value limit of constituent--quark mass. It is shown that this…
We calculate the electromagnetic form factor of the pion in lattice gauge theory. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the O(a) improved current. The form factor is compared to results…
We use recent data on K^+ -> pi^+ e^+ e^-, together with known values for the pion form factor, to derive experimental values for the kaon electromagnetic form factor for 0 < q^2 < 0.125 (GeV/c)^2. The results are then compared with the…
Pion transition form factor for the process $\gamma*\gamma*\to \pi^0$ at space-like values of photon momenta is calculated within the effective quark-meson model with the interaction induced by instanton exchange. The leading and…
In a Poincare'-covariant vector-boson-exchange theory, the pion possesses components of pseudovector origin, which materially influence its observable properties. For a range of such quantities, we explore the consequences of a…
The renormalizable Abelian quantum field theory model of Kroll, Lee, and Zumino is used to compute the one-loop vertex corrections to the tree-level, Vector Meson Dominance (VMD) pion form factor. These corrections, together with the known…
Recent data from high statistics experiments that have measured the modulus of the pion electromagnetic form factor from threshold to relatively high energies are used as input in a suitable mathematical framework of analytic continuation…
We compute the electromagnetic form factor of the pion using non-perturbatively O(a) improved Wilson fermions. The calculations are done for a wide range of pion masses and lattice spacings. We check for finite size effects by repeating…
Point-form relativistic quantum mechanics is used to derive an expression for the electromagnetic form factor of a pseudoscalar meson for space-like momentum transfers. The elastic scattering of an electron by a confined quark-antiquark…
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) ~ 1.2 GeV and allows a model-independent…
We consider a bottom-up AdS/QCD model with a conformal exponential deformation $e^{k\,z^2}$ on a Lorentz invariant AdS background. In this model, we assume the conformal dimension associated with the operator that creates pions at the…
We discuss the nonleading, ``soft" contribution to the pion form factor at intermediate momentum transfer within operator product expansion approach. We argue, that the corresponding contribution can temporarily {\bf simulate} the leading…