Related papers: Exchange currents in radiative hyperon decays and …
A short overview of motivations and successes of two-body exchange currents between constituent quarks for electromagnetic hadron observables like charge radii, magnetic and quadrupole moments is given. We then predict and analyze exchange…
We calculate the radiative decay widths of decuplet hyperons in a chiral constituent quark model including electromagnetic exchange currents between quarks. Exchange currents contribute significantly to the E2 transition amplitude, while…
Octet hyperon charge radii are calculated in a chiral constituent quark model including electromagnetic exchange currents between quarks. In impulse approximation one observes a decrease of the hyperon charge radii with increasing…
The exchange charge density operators that correspond to the Fermi-invariant decomposition of quark-quark interactions have been constructed. Their effect on the electromagnetic charge radii of the nucleons, in combination with that of the…
The chiral quark model gives a reasonably good description of many low-energy observables by incorporating the effective degrees carried by the constituent quarks and Goldstone bosons. We calculate the decuplet to octet transition magnetic…
The radiative decays of hyperons are studied in the framework of the bound state soliton model. Detailed predictions for the total decay widths and the E2/M1 ratios corresponding to decuplet--to--octet electromagnetic transitions are…
We calculate photoexcitation amplitudes for several nucleon and delta resonances. We use a chiral quark model including two-body exchange currents. The two-body currents give important contributions. For the delta (1232) and the D13 (1520)…
Electromagnetic properties provide information about the structure of strongly interacting systems and allow for independent tests of hadronic models. The radiative decay of the Delta(1700) is studied, which appears dynamically generated in…
We discuss the strong and radiative decays of the decuplet of baryon resonances to the baryon octet in chiral perturbation theory. We comment on the implications for the polarisability of the nucleon.
The electromagnetic decays of the ground state baryon multiplets with one heavy quark are calculated using Heavy Hadron Chiral Perturbation Theory. The M1 and E2 amplitudes for S^{*}--> S gamma, S^{*} --> T gamma and S --> T gamma are…
The radiative decays of $D^*$, $B^*$, and other excited heavy mesons are analyzed in a relativistic quark model for the light degrees of freedom and in the limit of heavy quark spin-flavor symmetry. The analysis of strong decays carried out…
A survey of the experimental data on the charge and strong hadronic radii is given. A new, however preliminary value of the \Sigma^- charge radius allows to include also hyperons in the systematics. The presented data on the hadronic radii…
We compute the leading contribution to the E2/M1 mixing ratio of the decay $\Delta\rightarrow N\gamma$ in heavy baryon chiral perturbation theory. We find the mixing ratio to be $4\% \ltap |\delta_{\rm E2/M1}| \ltap 11\%$, much larger than…
\pi and \eta decay modes of light baryon resonances are investigated within a chiral quark model whose hyperfine interaction is based on Goldstone-boson exchange. For the decay mechanism a modified version of the 3P0 model is employed. Our…
The non-leptonic hyperon decays are analyzed up to one-loop order including all counterterms in the framework of heavy baryon chiral perturbation theory. We use the exchange of the spin-3/2 decuplet resonances as an indication of which…
We investigate the leading-order amplitudes for weak radiative decays of hyperons in chiral perturbation theory. We consistently include contributions from the next-to-leading order weak-interaction Lagrangian. It is shown that due to these…
Relativistic exchange current corrections to neutrino--nucleus cross sections are presented assuming non--vanishing strange quark form factors for the constituent nucleons. For charged current processes the exchange current corrections can…
Radiative decays of heavy baryons are analyzed within the Heavy Quark Symmetry (HQS). It is shown that employing the light-diquark symmetries, the number of electromagnetic couplings among S-wave and P-wave states as well as those between…
The importance of resonances for the radiative hyperon decays is examined in the framework of chiral perturbation theory. Low lying baryon resonances are included into the effective theory and tree contributions to these decays are…
It is pointed out that the radiative decays of a $\phi$ meson, $\phirho$ and $\phiom$, receive dominant contributions from the pseudoscalar ($P = \eta, \eta^{'}$) exchanges. Using the vector meson dominance model, we find that $B (\phirho)…