Strange Tribaryons as Nona-quarks

Yuu Maezawa (Univ. Tokyo)Tetsuo Hatsuda (Univ. Tokyo)Shoichi Sasaki (RIKEN BNL)

hep-ph/0412025

IntroductionIntroduction

Spin and Parity are undetermined.

Strange tribaryon @KEK-PS

T. Suzuki et al. Phys. Lett. B 597 (2004) 263M. Iwasaki et al. hep-ph/0310018

(i) High density puzzle

NNNK 3310 MeV

TheoryppnK

(ii) Isospin puzzle

-110 MeV

)3140(S

)3115(0SppnK

pnnK

High central

Density 010~

)channel 0(- IpKStrong attraction

Akaishi and Yamazaki PRC65 (`02) 044005Dote, Horiuchi, Akaishi and Yamazaki, PRC70 (`04) 044313Hadronic pictureHadronic picture

state bound )1405( NK

I=0 I=1

Exp.Model

?

Nona-quark pictureNona-quark picture

uuudddddspnnKS :0

Nona-quark picture

0S

Possible other nona-quark states

Classification in color, flavor and spin space

Mass formula based on MIT bag model

flavor 27-plet

irreducible representation in flavor spin space

Classification in color, flavor and spin spaceClassification in color, flavor and spin spaceAll quarks are in lowest orbital angular momentum.

Degrees of freedom of nona-quark system

anti-symmetriccolor-singlet

Possible multiplets for and )3140(S)3115(0S)1,1(),(0 ISS

)1or 0,1(),( ISS

plet-27 -plet*35

0S SSS

I3

1

Mass formulaMass formula 　　 (Bag model)(Bag model)Aerts et al., PRD 17 (1977) 260.

Constant independent of quantum numbers

Adjusted to reproduce )3115(0S

breaking effect)3(FSU

More strange-quarks Larger mass

spin

Color-magnetic int. effect

flavor multipletLarger Larger mass

small

Parameters

MeV 285Sm• strange quark mass octet baryon

• bag radius 34/1

3 RR NN fm 13 R fm 3.19 R

• strong coupling constant 2.0 and 0.1S

strange mass effect+ flavor dependent effect by CM-int.+ spin, isospin effects

)21,1,27(),,( JIF

MeV21

(due to compact 9-quark structure?)

)3115(0S

Masses of strange tribaryonMasses of strange tribaryon

0S

)3115( vs)3140( 0SS

Case 1 state)21,0*,35(

Case 2 state)21,1,27(

isospin partner of S 0SMeV 00 SS

Case 3 state)23,1,27(

MeV40200 SSspin splitting of CM-int.

Too large ?

Too small ?

Nona-quark picture vs. hadronic pictureNona-quark picture vs. hadronic picture

0S

(i) High density puzzle

NOT a puzzle in the quark picture

(ii) Isospin puzzleNOT a puzzle in Case 1,2,3

Not seen yet ?

system ppnK

Other light nona-quarks ?Other light nona-quarks ?largeS Small flavor multiplets

are allowed. Color-magnetic int. small.

0.2S 0.1S

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?

SummarySummary

0S )2/1,1,27(),,( JIF

Narrow decay width ( < 21 MeV)

Other interactions (Meson cloud, Instanton induced int. …)

S

Future problems3for )2/3,1,1(2for )2/1,2/1,8(1for )2/1,0*,10(

SSS

Back up slides

Masses of strange tribaryonMasses of strange tribaryon

ColorMagneticInt.

strange mass effect flavor dependent effect in CM-int.