1. Strange Tribaryons as Nona-quarks Yuu Maezawa (Univ. Tokyo) Tetsuo Hatsuda (Univ. Tokyo) Shoichi Sasaki (RIKEN BNL) hep-ph/0412025

2. Introduction Spin and Parity are undetermined. Strange tribaryon @KEK-PS T. Suzuki et al. Phys. Lett. B 597 (2004) 263 M. Iwasaki et al. hep-ph/0310018

3. (i) High density puzzle 3310 MeV (ii) Isospin puzzle -110 MeV High central Density Strong attraction Akaishi and Yamazaki PRC65 (`02) 044005 Dote, Horiuchi, Akaishi and Yamazaki, PRC70 (`04) 044313 Hadronic picture I=0 I=1 Exp. Model ?

4. Nona-quark picture Possible other nona-quark states Classification in color, flavor and spin space Mass formula based on MIT bag model flavor 27-plet

5. irreducible representation in flavor spin space Classification in color, flavor and spin space All quarks are in lowest orbital angular momentum. Degrees of freedom of nona-quark system anti-symmetric color-singlet

6. Possible multiplets for and S I3I3

7. Mass formula (Bag model) Aerts et al., PRD 17 (1977) 260. Constant independent of quantum numbers Adjusted to reproduce breaking effect More strange-quarks Larger mass spin Color-magnetic int. effect flavor multiplet Larger Larger mass

8. small Parameters strange quark massoctet baryon bag radius strong coupling constant

9. strange mass effect + flavor dependent effect by CM-int. + spin, isospin effects (due to compact 9-quark structure?) Masses of strange tribaryon

10. Case 1 state Case 2 state isospin partner of Case 3 state spin splitting of CM-int. Too large ? Too small ?

11. ここにスライド３に対する答えをまとめる Nona-quark picture vs. hadronic picture (i) High density puzzle NOT a puzzle in the quark picture (ii) Isospin puzzle NOT a puzzle in Case 1,2,3 Not seen yet ?

12. Other light nona-quarks ? Small flavor multiplets are allowed. Color-magnetic int. small.

13. Strangeness tribaryon nona-quark description Classification in flavor-spin space and mass formula is identified as Three possible interpretations of are given. other light nona-quark states? Summary Narrow decay width ( < 21 MeV) Other interactions (Meson cloud, Instanton induced int. …) Future problems

14. Back up slides

15. Masses of strange tribaryon Color Magnetic Int. strange mass effect flavor dependent effect in CM-int.