1. Introduction

2. Exotic properties of K nuclei

3. To go forward (Future plan)

4. Summary

Dense K nuclei- To go forward -Dense K nuclei

- To go forward -

KEK Nuclear workshop @ KEK, ’06.Aug.3

A. Dote （ KEK ）

´

Y. Akaishi (Nihon univ.) T. Yamazaki (RIKEN) W. Weise (TU Muenchen)

Introduction

What are kaonic nuclei (K nuclei)?

K- meson is bound in a nucleus by strong interaction.

cf) Kaonic atom K- meson is around a nucleus, bound by Coulomb interaction.

K nuclei can exist as discrete states, since K- meson is deeply bound below Σπ threshold.

KNNN…

ΣπNN…

K nuclear state

K nuclear state

Deeply bound; Binding energy of K- > 100 MeVDiscrete state; Below Σπ threshold

Very attractive I=0 KN interaction makes …

... Deeply bound kaonic nuclei

1. free KN scattering data2. 1s level shift of kaonic hydrogen atom3. binding energy and width of Λ(1405)

Phenomenological KN potential (AY KN potential)

Strongly attractive.

0KN

IV 0KN

IV

Y. Akaishi and T. Yamazaki, PRC 52 (2002) 044005

= K- + proton

0 11 34

4 4I Ig g

0 1

2

13

2

1 I Ig g

0 1

2

13

2

1 I Ig g

My motivation

Only one K- meson can drastically change the nuclear structure?

Only one K- meson can drastically change the nuclear structure?

Y. Akaishi and T. Yamazaki, PRC 52 (2002) 044005

8Be + K-

… Akaishi’s special lecture held in Kyoto university in ’00.

Exotic features of K nuclei

Fully microscopic treatment

No assumption on nuclear structure; cluster, deformation …

System self-organizes only following energy variation.

p

n

Normal nucleus

p

n

normal nucleus

? ?? ?? ?? ?

Kaonic nucleus

What kind of structure does A+1 system favor?

Antisymmetrized Molecular Dynamics （ AMD ）Antisymmetrized Molecular Dynamics （ AMD ）

K- meson = a seed of strong attraction

☆ Improve AMD for K nuclei

mixing- 0K p-K n

-K p 0K n

0KN

IV 0KN

IV

0

proton neutronN a b

K x K y K

+ Charge projection of total wave function

Single nucleon/kaon wave function

Hamiltonian in AMD calculation

CMNN KN CoulombH T V V V T

: effective NN int. 　　　　　　　　 Tamagaki potential (OPEG)

: effective KN int. 　　　　　　　　 AY KN potential

NNV

KNV

G-matrix method Y. Akaishi and T. Yamazaki, PRC 52 (2002) 044005

Deep potential

Y. AkaishiT. Yamazaki

A. DoteW. Weise

Shallow potential

E. OsetH. TokiA. Gal

vs

Akaishi-san’s talk Prof. Oset’s talk

A. D., H. Horiuchi, Y. Akaishi and T. Yamazaki, PLB 590 (2004) 51; PRC 70 (2004) 044313.

AMD studies revealed …

1. E(K) > 100 MeV for various light nuclei

2. Drastic change of the structure of 8Be, isovector deformation in 8BeK-

3. Highly dense state is formed in K nuclei. maximum density > 4ρ0

averaged density 2 ～ 4ρ0

4. Proton satellite in pppK-

Rrms = 2.46 fmβ = 0.63

Central density = 0.10 /fm^3

8Be

Density (/fm^3) 0.0 0.10 0.20

-160.0

-140.0

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0ppnK pppK pppnK 6BeK 8BeK 9BK

E(K)

[M

eV]

Nucleus-K- 　 threshold

Σπ threshold

(simple AMD)

Width (Σπ, Λπ)

Rrms = 1.42 fmβ = 0.55

Central density = 0.76 /fm^3

8BeK-

Density (/fm^3) 0.0 0.41 0.83

4.5 normal density

Binding energy of K- = 104 MeV

Isovector deformation

0 1KN

IIKNVV

K p K nV V

pppK-

Proton satellite

Various shapes of K nuclei

ppnK- pppK- pppnK-

6BeK-

3 fm

9BK-

4 fm

8.8ρ0 9.2ρ0 7.6ρ0

5.4ρ0 4.1ρ0

1.141.67 1.78

2.55 2.53

1( )

5 MAX K

4 fm

4.1ρ0

Single K- meson can interact with limited numbers of nucleons?

Saturation of E(K)

E(K) width ρ (0)[MeV] [MeV] [fm̂ - 3]

ppnK- 110.3 21.2 1.50pppK- 96.7 12.5 1.56pppnK- 105.0 25.9 1.296BeK- 104.2 33.3 0.919BK- 118.5 33.0 0.7111CK- 117.4 46.0 0.81

① 　 Deeply bound and Dense

③ 　 Isovector deformation ④ 　 proton satellite

pppK-

② 　 Drastic change of structure

8Be 8BeK-

Various groups are trying to search for deeply bound kaonic nuclei in various way.

T. Suzuki, M.Iwasaki et al; 4He(stopped K-, n or p) @ KEK ppnK-: B.E. = 169MeV, pnnK-: B.E. = 195MeV

H. Fujioka, T. Nagae et al; ppK- @ DAΦNE ppK-: B.E. = 116MeV

Kishimoto et al; 16O(inflight K-, n) 15OK- @ BNL

• N.Herrmann et al; Invariant-mass method (heavy-ion collision) @ GSI ppnK-: B.E. ～ 150MeV (preliminary)

• K. Suzuki et al; proton induced reaction @ GSI

• J-PARC

• The technique of conventional nuclear physics• Phenomenological KN interaction

• Experimental results are coming up.

K nucleus has very exotic properties!

真実Truth

To go forward

1, Short-range repulsive core part of NN interaction The repulsive core part of the effective NN potential derived by G-matrix method is too much smoothed out for the study of kaonic nuclei?

“Beyond the conventional nuclear physics”

3, Mystery of two-body absorption (KNN --> YN) … large decay width at high density K nuclei can survive?

2

2, Using more theoretical KN interaction• Energy- and density-dependence• I=1 P-wave interaction … Attractive below Σ(1385). … Large contribution at high density?

,KN P waveV C r

EEEEEEEEEEEEEEEEEEEEEEEEEEEE

Additional attraction to

deeply bound kaonic nuclei

To go forward … Collaborating withW. Weise

This part

is undergoing…This part

is undergoing…

Summary Kaonic nuclei have interesting properties!

The AMD study with AY KN interaction showed …

• K- is deeply bound by ～ 100 MeV and forms highly dense state.

• Strange structures appear in K nuclei. Drastic change of 8Be structure, Isovector deformation in 8BeK-, Proton satellite in pppK-.

Study more various K nuclei

Double K nuclei?

Other type of KN interaction?

Many experiments will start, or started.

T. Suzuki, Iwasaki et al; 4He(stopped K-, n or p) @ KEK Fujioka, Nagae et al; ppK- @ DAΦNE Kishimoto et al; 16O(inflight K-, n) 15OK- @BNL• Herrmann et al; Invariant-mass method (heavy-ion collision) @ GSI• K. Suzuki et al; proton induced reaction @ GSI• J-PARC

I=1 p-wave KN interaction … suggested by S. Wycech et al. 　 nucl-th/0501019Collaborate with W. Weise

Study K nuclei from the viewpoint of quarksCollaborate with Y. Kanada-En’yo and O. Morimatsu

Λ(1405) = qqq-qq, ppK- = 7qq, ppnK- = 10qq (undeca-quarks state)- - -

Apply our wave function to the study of reaction

Dense or not? (S. Hirenzaki and J. Yamagata)

Future plans

Kaonic nucleus

K nuclei… 　 Exotic system !

… related to various fields!!

KN interaction

Cold and Dense

Kaonic atom

Λ （１４０５）

Interesting structure… Nuclear structure

Kaon condensation

(Strange) Quark matter

Chiral symmetry restoration