ﻻ يوجد ملخص باللغة العربية
Compton scattering off the proton in the third resonance region is analyzed for the first time, owing to the full combined analysis of pion- and photo-induced reactions in a coupled-channel effective Lagrangian model with K-matrix approximation. Two isospin $I=3/2$ resonances $D_{33}(1700)$ and $F_{35}(1930)$ are found to be essential in the range of 1.6 - 1.8 GeV. The recent beam asymmetry data of Compton scattering from the GRAAL facility are used to determine the helicity couplings of these resonances, and strong constraints are coming also from $pi N$ and $KSigma$ photoproduction data. The possible spin and parity of new narrow resonances is discussed.
We investigate the spin-independent part of the virtual Compton scattering (VCS) amplitude off the nucleon within the framework of chiral perturbation theory. We perform a consistent calculation to third order in external momenta according to Weinber
The unpolarized and polarized Beam Char-ge Asymmetries (BCAs) of the $vv{e}^{pm}p to e^{pm}p gamma$ process off unpolarized hydrogen are discussed. The measurement of BCAs with the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Faci
We report on new measurements of the electric Generalized Polarizability (GP) of the proton $alpha_E$ in a kinematic region where a puzzling dependence on momentum transfer has been observed, and we have found that $alpha_E = (5.3 pm 0.6_{stat} pm 1.
We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q^2 = 1.3 GeV^2. Using the Jefferson Lab polarized electron beam, a spectrometer, and a pola
We present a unified relativistic approach to inclusive electron scattering based on the relativistic Fermi gas model and on a phenomenological extension of it which accounts for the superscaling behaviour of $(e,e)$ data. We present results in the $