Structure of heavy baryons in a pion mean-field approach

In this talk, we briefly review a series of recent works on singly heavy baryons, based on a pion mean-field approach. In the limit of the infinitely heavy quark mass, heavy baryons are governed mainly by the light degress of freedom. Taking the number of colors to be infinity, a heavy baryon arises as a state consisting of $N_c-1$ valence quarks bound by the pion mean fields created self-consistently. Within this framework, we present the results of the mass spectra of the charmed and bottom baryons, and their magnetic moments. The behavior of the electromagnetic form factors will be also mentioned.Comment: 4 pages, No figure. Contribution to the proceedings of "8th International Conference on Quarks and Nuclear Physics (QNP2018)", November 13-17, 2018, Tsukuba, Japa

K0ΛK^0\Lambda Photoproduction with Nucleon Resonances

We investigate the reaction mechanism of $K^0 \Lambda$ photoproduction off the neutron target, i.e., $\gamma n \to K^0 \Lambda$, in the range of $W\approx 1.6-2.2$ GeV. We employ an effective Lagrangian method at the tree-level Born approximation combining with a Regge approach. As a background, the $K^*$-Reggeon trajectory is taken into account in the $t$ channel and $\Lambda$ and $\Sigma$ hyperons in the $u$-channel Feynman diagram. In addition, the role of various nucleon resonances listed in the Particle Data Group (PDG) is carefully scrutinized in the $s$ channel where the resonance parameters are extracted from the experimental data and constituent quark model. We present our numerical results of the total and differential cross sections and compare them with the recent CLAS data. The effect of the narrow nucleon resonance $N(1685,1/2^+)$ on cross sections is studied in detail and it turns out that its existence is essential in $K^0 \Lambda$ photoproduction to reproduce the CLAS data.Comment: 4 pages, 3 figures, Proceedings of "8th International Conference on Quarks and Nuclear Physics (QNP2018)", November 13-17, 2018, Tsukuba, Japa

Electromagnetic form factors of the baryon decuplet with flavor SU(3) symmetry breaking

We investigate the electromagnetic form factors of the baryon decuplet within the framework of the $\mathrm{SU(3)}$ self-consistent chiral quark-soliton model, taking into account the $1/N_c$ rotational corrections and the effects of flavor $\mathrm{SU(3)}$ symmetry breaking. We first examine the valence- and sea-quark contributions to each electromagnetic form factor of the baryon decuplet and then the effects of the flavor SU(3) symmetry breaking. The present results are in good agreement with the recent lattice data. We also compute the charge radii, the magnetic radii, the magnetic dipole moments and the electric quadrupole moments, comparing their results with those from other theoretical works. We also make a chiral extrapolation to compare the present results with the lattice data in a more quantitative manner. The results show in general similar tendency to the lattice results. In particular, the results of the $M1$ and $E2$ form factors are in good agreement with those of lattice QCD.Comment: 29 pages, 15 figures. Comparison with the lattice data was elaborate