Related papers: Octet baryon electromagnetic form factor double ra…
In contrast with common non-relativistic lore, the usual Sachs form factors are not the Fourier transforms of charge or magnetization densities. Instead, the two-dimensional Fourier transform of the electromagnetic $F_1$ form factor is the…
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…
The electromagnetic transition moments of the $SU(3)$-flavor baryon octet to decuplet are examined within a lattice simulation of quenched QCD. The magnetic transition moment for the $N \; \gamma \to \Delta$ channel is found to be in…
The ratio of the transverse and longitudinal component of polarization transfer to protons in the quasi-elastic $(\vec{e}, e^{\prime} \vec{p}\,)$ reaction, $P^{\prime}_x/P^{\prime}_z$, is sensitive to the proton's electromagnetic form…
We study net-baryon number density fluctuations in isospin-symmetric matter near the nuclear liquid-gas phase transition using the parity doublet model. We analyze second-order susceptibilities of net-proton and net-neutron numbers and…
It is demonstrated how an utilization of all existing experimental information on electric and magnetic nucleon form factors, to be described by the Unitary and Analytic (U\&A) nucleon electromagnetic structure model in space-like and…
In these proceedings we present preliminary results for the masses of the proton, neutron and $\Omega^-$ baryons obtained from QCD+QED lattice simulations performed with four dynamical quarks using C$^*$ boundary conditions. These results…
Results for the proton and neutron electric and magnetic form factors as well as the nucleon axial form factor are presented for constituent quark models, based on either one-gluon-exchange and Goldstone-boson-exchange dynamics. The…
We discuss questions related to the interpretation of unexpected results of measurements of the proton form factors ratio G_E/G_M in the polarization experiments done in JLab in the region of 0.5 < Q^2 < 8.5 GeV^2. For this purpose, in the…
The electromagnetic form factors $G_{\rm E}$ and $G_{\rm M}$ of the proton and neutron in the timelike region are extracted in a study of the processes $e^+ e^-\to \bar{p}p$ and $e^+ e^-\to \bar{n}n$. The reaction amplitude is evaluated…
The effect of one-gluon-exchange (OGE) pair-currents on the ratio $\mu_p G_E^p/G_M^p$ for the proton is investigated within a nonrelativistic constituent quark model (CQM) starting from $SU(6) \times O(3)$ nucleon wave functions, but with…
Nucleon properties are modified in the nuclear medium. To understand these modifications and their origin is a central issue in nuclear physics. For example, a wide variety of QCD-based models, including quark-meson coupling and…
The parameter-free predictions for the $N - P_{11}(1440)$ and $N - P_{33}(1232)$ electromagnetic transition form factors, obtained within our light-front constituent quark model using eigenfunctions of a baryon mass operator which includes…
The magnetic moments of baryon decuplet are studied in vacuum as well as in the symmetric nuclear matter at finite temperature using a chiral SU(3) quark mean field model approach. The contributions coming from the valence quarks, quark sea…
Here we present preliminary results for the evaluation of the electromagnetic form factors for the lowest-lying negative-parity, spin-$\frac{1}{2}$ nucleons, namely the $S_{11}(1535)$ and $S_{11}(1650)$, through the use of the variational…
At present there exists a great interest in the search for evidence of possible modification of the nucleon form factors inside the nuclear medium. Recent theoretical work predict changes in the form factors within the experimental limits.…
Baryon magnetic moments and beta decay ratios ($G_A/G_V$) are calculated in a phenomenological quark model. Non-static effects of pion exchange and orbital excitation are included. Good agreement with experiment is found for a combined fit…
The ratio $R_p$ between the electric and magnetic proton form factors has been recently measured at JLab up to $Q^2=8.5 ~GeV^2$. We have extended the calculation of the nucleon form factors with the hypercentral Constituent Quark Model and…
The magnetic moment---a function of the electric charge form factor $F_{1}(q^{2})$ and the magnetic dipole form factor $F_{2}(q^{2})$ at zero four-momentum transfer $q^{2}$---of the ground-state $U$-spin =3/2 baryon decuplet $\Delta^{-}$,…
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…