1. 5 th APFB Conference August 22-26, 2011, Seoul, Korea Hyperons analogous to  Yongseok Oh (Kyungpook National University, Korea)

2. 2011-08-23 APFB 2011, Seoul, Korea 2 Overview 1.Introduction 2.Bound state approach to the Skyrme model 3.Outlook

3. 2011-08-23 APFB 2011, Seoul, Korea 3 Hyperon spectrum –Completeness of the observed hyperon resonances –Theoretical models for hyperon structure –Structure of  (1405) uds Five quark K-bar N bound state -  baryon analogous to  (1405)? 1. Introduction PDG

4. 2011-08-23 APFB 2011, Seoul, Korea 4  spectrum Cf. spin of W- (=3/2) was confirmed only recently by BaBar, PRL 97 (2006) P is not directly measured

5. 2011-08-23 APFB 2011, Seoul, Korea 5 Experiments on multi-strangeness PDG 2008 No meaningful information on  spectrum Open a new window for studying baryon structure

6. 2011-08-23 APFB 2011, Seoul, Korea 6 Questions The 3 rd lowest state CLAS: PRC 76 (2007) Babar: J P of  (1690) is 1/2  PRD78 (2008)

7. 2011-08-23 APFB 2011, Seoul, Korea 7 Summary QM (Pervin, Roberts) 1325 1891 2014 PRC 75 1520 1934 2020 1725 1811 1759 1826 1820 (expt.) 1320 (expt.) 1530 (expt.) : the 3 rd lowest state Expt:  (1620)*,  (1690)***

8. 2011-08-23 APFB 2011, Seoul, Korea 8 Highly model-dependent !

9. 2011-08-23 APFB 2011, Seoul, Korea 9 2. Bound state approach to the Skyrme model bound kaon SU(3) is badly broken Treat light flavors and strangeness on the different footing L = L SU(2) + L K/K* Soliton provides background potential which traps K/K* (or heavy) meson Bound state approach (Callan, Klebanov)

10. 2011-08-23 APFB 2011, Seoul, Korea 10 Bound state model 270 MeV energy difference Includes parameters They should be computed with a given Lagrangian (dynamics). Or fix them to known masses and then predict. Mass formula

11. 2011-08-23 APFB 2011, Seoul, Korea 11 Some details Other approaches Kaons: one in p-wave and one in s-wave J=J sol + J m (J m = J 1 + J 2 ) J sol : soliton spin (=1/2), J 1 (J 2 ): spin of the p(s)-wave kaon (=1/2) J m = 0 and 1: both of them can lead to J P = 1/2 -  states Therefore, two J P = 1/2 -  states and one J P = 3/2 -  state In this model, it is natural to have two J P = 1/2 -  states and their masses are close to each other. Clearly, different from quark models Unitarized extension of chiral perturbation theory Ramos, Oset, Benhold PRL 89 (2002) 1/2 - state at 1606 MeV Garxia-Recio, Lutz, Nieves, PLB 582 (2004)  (1620) and  (1690) are 1/2 - states

12. 2011-08-23 APFB 2011, Seoul, Korea 12 Hyperon spectrum 289 MeV 290 MeV 285 MeV positive parity negative parity parity undetermined

13. 2011-08-23 APFB 2011, Seoul, Korea 13 Hyperon spectrum YO, PRD 75 (2007) spin-parity Recently confirmed by COSY PRL 96 (2006) High precision experiments are required!  ’s would be discovered in future. Babar: J P of  (1690) is 1/2 - PRD 78 (2008) NRQM predicts 1/2 +

14. 2011-08-23 APFB 2011, Seoul, Korea 14 Outlook

15. 2011-08-23 APFB 2011, Seoul, Korea 15 Similar mass splitting between parity partners –  c (1/2 + ): 2286 MeV,  c (1/2 - ): 2595 MeV –The mass difference between the two = 309 MeV –Potential is almost flavor-blind but gives richer spectrum for heavy-quark baryons –More analyses are needed Heavy quark baryons