Octet, decuplet, and antidecuplet magnetic moments in the chiral quark soliton model reexamined

We reanalyze the magnetic moments of the baryon octet, decuplet, and antidecuplet within the framework of the chiral quark-soliton model, with SU(3) symmetry-breaking taken into account. We consider the contributions of the mixing of higher representations to the magnetic moment operator arising from the SU(3) symmetry-breaking. Dynamical parameters of the model are fixed by experimental data for the magnetic moments of the baryon octet and from the masses of the octet, decuplet and of ${\Theta }^{+}$. The magnetic moment of ${\Theta }^{+}$ depends rather strongly on the pion-nucleon sigma term and reads $-1.19\mathrm{n}\mathrm{m}$ to $-0.33\mathrm{n}\mathrm{m}$ for ${\Sigma }_{\pi N}=45$ and 75 MeV, respectively. The recently reported mass of ${\Xi }_{\overline{10}}^{--}(1862)$ is compatible with ${\Sigma }_{\pi N}=73\mathrm{M}\mathrm{e}\mathrm{V}$. As a by-product the strange magnetic moment of the nucleon is obtained with a value of ${\mu }_N^{(s)}=+0.39\mathrm{n}\mathrm{m}$.

Figure 1

Magnetic moments of antidecuplet as functions of ${\Sigma }_{\pi N}$.

Figure 2

Dependence of magnetic moments on $m_s$ for ${\Sigma }_{\pi N}=45$ and 75 MeV.