Related papers: N->Delta Quadrupole Transition in the Constituent …
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…
In this brief pedagogical overview the physical basis of the deviation of the nucleon shape from spherical symmetry will be presented along with the experimental methods used to determine it by the gamma* p -> Delta reaction.The fact that…
Electroproduction form factors describing the $\gamma^\ast p \to \Delta^+(1232), \Delta^+(1600)$ transitions are computed using a fully-dynamical diquark-quark approximation to the Poincar\'e-covariant three-body bound-state problem in…
We report new precise H$(e,e^\prime p)\pi^0$ measurements at the $\Delta(1232)$ resonance at $Q^2= 0.127$ (GeV/c)$^2$ using the MIT/Bates out-of-plane scattering (OOPS) facility. The data reported here are particularly sensitive to the…
The collective structure of atomic nuclei intermediate between spherical and quadrupole deformed structure presents challenges to theoretical understanding. However, models have recently been proposed in terms of potentials which are soft…
The paper contains a systematic, model-independent treatment of electric dipole (E1) transitions in heavy quarkonium. Within the effective field theory framework of potential non-relativistic QCD (pNRQCD), we derive the complete set of…
We evaluate the two-photon exchange contribution to the $e N \to e \Delta(1232) \to e \pi N$ process at large momentum transfer with the aim of a precision study of the ratios of electric quadrupole (E2) and Coulomb quadrupole (C2) to the…
We present a theroretical treatment of electric dipole (E1) transitions of heavy quarkonia based on effective field theories. Within the framework of potential nonrelativistic QCD (pNRQCD) we derive the complete set of relativistic…
Electric quadrupole (E2) matrix elements provide a measure of nuclear deformation and related collective structure. Ground-state quadrupole moments in particular are known to high precision in many p-shell nuclei. While the experimental…
Using recent experimental data, we analyze the electromagnetic transition from the nucleon to the P11(1440) resonance. From the resulting empirical transition form factors, we map out the quark transverse charge densities which induce the N…
The resonant electric quadrupole amplitude in the transition $\gamma N\leftrightarrow\Delta(1232)$ is of great interest for the understanding of baryon structure. Various dynamical models have been developed to extract it from the…
We propose a systematic, model-independent treatment of electric dipole transitions of heavy quarkonium. Within an effective field theory, concretely potential non-relativistic QCD, the relativistic corrections of relative order $v^2$ to…
The weak $\Lambda N\to NN$ transition is studied in the valence quark model approach. The quark component of the two baryon system is described in the quark cluster model and the weak transition potential is calculated by evaluating the…
A phenomenological Lagrangian approach is employed to study the electromagnetic properties of the deuteron. The deuteron is regarded as a weakly bound state of the proton and neutron. We construct a general form for the electromagnetic one-…
For electric quadrupole ($E2$) observables, which depend on the large-distance tails of the nuclear wave function, ab initio no-core configuration interaction (NCCI) calculations converge slowly, making meaningful predictions challenging to…
We identify here possible occurrence of large deformations in the neutron- and proton-rich regions of the nuclear chart from extensive predictions of the values of the reduced quadrupole transition probability B-E2 for the transition from…
The first direct experimental observation of an electric quadrupole ($\textit{E}$2) transition between bound states of an atomic negative ion has been made. The transition was observed in the negative ion of bismuth by resonant (1+1)…
The evolution of quadrupole and octupole shapes in Th isotopes is studied in the framework of nuclear Density Functional Theory. Constrained energy maps and observables calculated with microscopic collective Hamiltonians indicate the…
We utilize non-perturbative and fully relativistic methods to calculate the\thinspace \thinspace $\Delta N\gamma $ electromagnetic transition amplitudes $G_{M}^{*}(q^{2})$ (related to the magnetic dipole moment $% M_{1^{+}}^{3/2}(q^{2})$),…
The measurement of a permanent electric dipole moment (EDM) in atoms is crucial for understanding the origins of CP-violation. However, accurate interpretation of the EDM in systems involving deformed isotopes requires the characterization…