相关论文: Connection between the elastic GEp/GMp and P to De…
The purely nonperturbative soft contribution to the $\gamma^* p \to \Delta^+$ transition form factors is estimated using the local quark-hadron duality approach. Our results show that the soft contribution is dominated by the magnetic…
We use local quark-hadron duality to estimate the purely nonperturbative soft contribution to the $\gamma^* p \to \Delta$ form factors. Our results are in agreement with existing experimental data. We predict that the ratio…
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 have reexamined the elastic pion form factor over a broad range of momentum transfers with the mass evolution from current quark to constituent quark being taken into account. We have also studied the effect of Sudakov form factors, of…
The C2/M1 ratio of the electromagnetic N->Delta(1232) transition, which is important for determining the geometric shape of the nucleon, is shown to be related to the neutron elastic form factor ratio G_C^n/G_M^n. The proposed relation…
We study the elastic electric and magnetic form factors of the proton, neutron and the charged roper resonance ($G_E^p$, $G_M^p$, $G_E^n$, $G_M^n$, $G_E^R$ and $G_M^R$) systematically in a constituent quark model. Three ingredients are…
We use local quark-hadron duality to estimate the purely nonperturbative soft contribution to the $\gamma^*p\to \Delta$ form factors. Our results are in agreement with existing experimental data. We predict that the ratio…
The elastic neutron form factors $G_{En}$ and $G_{Mn}$ are calculated in a GPD framework using GPDs obtained from fits to proton elastic form factors $G_{Ep}$ and $G_{Mp}$, and isospin symmetry, with no further changes in parameters. The…
We discuss the links between Generalized Parton Distributions (GPDs) and elastic nucleon form factors. These links, in the form of sum rules, represent powerful constraints on parametrizations of GPDs. A Regge parametrization for GPDs at…
The form factors for the hadron matrix element of the QCD energy-momentum tensor not only describe the coupling of the hadron with a graviton as the ``gravitational form factors'', but also serve as unique quantities for describing the…
The three electromagnetic form factors of the $\Delta(1232)$ resonance, $G^*_M(q^2)$, $G^*_E(q^2)$, and $G^*_C(q^2)$ are obtained in the space-like region using a Dual Resonance Model realization of QCD in the large $N_c$ limit…
We discuss the applicability of pQCD to the elastic scattering of electrons on protons and deuterons. We analyze the $Q^2$-dependence of the reduced deuteron form factor, taking into account the recent data on the electric proton form…
Within the dynamical model of Refs. [Phys. Rev. C54, 2660 (1996); C63, 055201 (2001)], we perform an analysis of recent data of pion electroproduction reactions at energies near the Delta(1232) resonance. We discuss possible interpretations…
We report a new measurement of the exclusive electroproduction reaction gamma* p -> pi0 p to explore the evolution from soft non-perturbative physics to hard processes via the Q2 dependence of the magnetic (M1+), electric (E1+) and scalar…
The leading one-loop corrections to the gravitational form factors of the delta resonance are calculated in the framework of chiral effective field theory. Various contributions to the energy-momentum tensor and the renormalization of the…
We compute nucleon and Delta elastic and transition form factors, and compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained…
The electron-graviton interaction can be described in terms of the gravitational form factors of the QED energy momentum tensor. Here we focus on the form factor D(t), and we examine its properties and its interpretation in terms of…
The new parameterization of the Generalized Parton Distributions (GPDs) t-dependence is investigated. It is shown that the new form of the GPDS allows one to reproduce sufficiently well the electromagnetic form factors of the proton and…
The nucleon elastic form factors are generally interpreted as a mapping of the charge and magnetic current distributions of the proton and neutron. New high Q^2 measurements have opened up fundamental questions about G_ep that remain to be…
Several years ago it was pointed out that the chiral soliton model allows naturally for satisfactory agreement with the experimentally well-determined proton magnetic form factor $G_M^p$. The corresponding result for the proton electric…