Magnetic and axial-vector transitions of the baryon antidecuplet
| Autor: | Kim, H. -Ch., Yang, Gh. -S., Goeke, K. |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Prog.Theor.Phys.Suppl.168:62-69,2007 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1143/PTPS.168.62 |
| Popis: | We report the recent results of the magnetic transitions and axial-vector transitions of the baryon antidecuplet within the framework of the chiral quark-soliton model. The dynamical model parameters are fixed by experimental data for the magnetic moments of the baryon octet, for the hyperon semileptonic decay constants, and for the singlet axial-vector constant. The transition magnetic moments $\mu_{\Lambda\Sigma}$ and $\mu_{N\Delta}$ are well reproduced and other octet-decuplet and octet-antidecuplet transitions are predicted. In particular, the present calculation of $\mu_{\Sigma\Sigma^*}$ is found to be below the upper bound $0.82\mu_N$ that the SELEX collaboration measured very recently. The results explains consistently the recent findings of a new $N^*$ resonance from the GRAAL and Tohoku LNS group. We also obtain the transition axial-vector constants for the $\Theta^+\to KN$ from which the decay width of the $\Theta^{+}$ pentaquark baryon is determined as a function of the pion-nucleon sigma term $\Sigma_{\pi N}$. We investigate the dependence of the decay width of the $\Theta^{+}$ on the $g_{A}^{(0)}$, with the $g_{A}^{(0)}$ varied within the range of the experimental uncertainty. We show that a small decay width of the $\Theta^{+}\to KN$, i.e. $\Gamma_{\Theta KN} \leq 1$ MeV, is compatible with the values of all known semileptonic decays with the generally accepted value of $g_{A}^{(0)} \approx 0.3$ for the proton. Comment: 8 pages, 5 figures, Talk given at the Yukawa International Seminar (YKIS) 2006, "New frontiers in QCD", Kyoto, Japan, 20 Nov. - 8 Dec. 2006 |
| Databáze: | arXiv |
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