exotic system: kaonic nuclei the present status and the future development
DESCRIPTION
A. Dote ( KEK ) Y. Akaishi (Nihon univ.) T. Yamazaki (RIKEN). ´. Exotic system: Kaonic nuclei the present status and the future development. Introduction Exotic properties of K nuclei Recent experimental results Strange tribaryons by KEK experiment ppK - by FINUDA - PowerPoint PPT PresentationTRANSCRIPT
1. Introduction
2. Exotic properties of K nuclei
3. Recent experimental results• Strange tribaryons by KEK experiment• ppK- by FINUDA• ppnK- by FOPI
4. Future developments
5. Summary and future plans
Exotic system: Kaonic nuclei the present status and the future development
QCD とハドロン物理の新展開 @ KEK, ’06.Mar.1
A. Dote ( KEK ) Y. Akaishi (Nihon univ.) T. Yamazaki (RIKEN)
´
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
Y. Akaishi and T. Yamazaki, PRC 52 (2002) 044005
= K- + proton
0 11 344 4
I Ig g
0 1
2132
1 I Ig g
My motivation
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 treatmentNo assumption on nuclear structure; cluster, deformation …
System self-organizes only following energy variation.
pn
Normal nucleus
pn
normal nucleus? ?? ?
? ?? ?
Kaonic nucleus
What kind of structure does A+1 system favor?
Anti-symmetrized Molecular Dynamics
Essence of AMD
det
det
det
Cooling
det
0s
0p
Shell
det
Cluster
Gaussian wave packet
AMD wave function can describe not only shell-model-like structure but also cluster-like one.
The structure is determined by only the energy-variation.
☆ Improve AMD for K nuclei
mixing- 0K p-K n
-K p 0K n0
KNIV
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
We used only central potential as VNN
before the discovery of strange tribaryons.
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)
[MeV
]
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 deformation0 1
KNIIKNVV
K p K nV V
pppK-
Proton satellite
Various shapes of K nucleippnK- 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)
Recent experimental results
T. Suzuki, M.Iwasaki et al; 4He(stopped K-, n or p) @ KEK
H. Fujioka, T. Nagae et al; ppK- @ DAΦNE
Kishimoto et al; 16O(inflight K-, n) 15OK- @ BNL
• N.Herrmann et al; Invariant-mass method (heavy-ion collision) @ GSI
• K. Suzuki et al; proton induced reaction @ GSI
• J-PARC
Various groups are trying to search for deeply bound kaonic nuclei in various way.
KEK group
ppnK-
(T=0)
4He (stopped K-, n) ppnK- 4He (stopped K-, p) pnnK-
pnnK-
(T=1)
T. Suzuki, M. Iwasaki et al
• KEK• Stopped K- reaction on 4He target• Missing-mass method (Detecting p or n)
ppnK- :Strange tribaryon S+(3140)
arXiv: nucl-ex/0310018
Total binding energy = 169 MeVDecay width < 25 MeV
pnnK- :Strange tribaryon S0(3115)
PLB 597, 263 (2004)
Total binding energy = 194 MeVDecay width < 21 MeV
FINUDA group H. Fujioka, T. Nagae et al
• e+e- collider DAΦNE, FINUDA spectrometer• K- absorbtion at rest on various nuclei• Invariant-mass method
Strong correlation between emitted p and Λ(back-to-back) Invariant mass of p and Λ
ppK-
Total binding energy = 115 MeVDecay width = 67 MeV
PRL 94, 212303 (2005)
6 35 4
14 211 3
FOPI group• GSI• Heavy-ion collision Ni+Ni @ 1.93 A GeV• Invariant-mass method
Invariant mass of d and Λ
N. Herrmann et al
ppnK-
Total binding energy = ~ 150 MeVDecay width = 100 MeV ?
Preliminary !
Summary of present status
Our predictions B.E. = 48 MeV
Γ = 61 MeVB.E. = 118 MeVΓ = 21 MeV
B.E. = 87 MeVΓ = 133 MeV
KEK B.E. = 169 MeVΓ < 25 MeV
B.E. = 194 MeVΓ < 21 MeV
FINUDA B.E. =115 MeVΓ = 67 MeV
FOPI B.E. ~ 150 MeVΓ ~ 100 MeV
ppK- ppnK- pnnK-
Summary of present status
Our predictions B.E. = 48 MeV
Γ = 61 MeVB.E. = 118 MeVΓ = 21 MeV
B.E. = 87 MeVΓ = 133 MeV
KEK B.E. = 169 MeVΓ < 25 MeV
B.E. = 194 MeVΓ < 21 MeV
FINUDA B.E. =115 MeVΓ = 67 MeV
FOPI B.E. ~ 150 MeVΓ ~ 100 MeV
ppK- ppnK- pnnK-
Experimental results are more deeply bound than ours.
Summary of present status
Our predictions B.E. = 48 MeV
Γ = 61 MeVB.E. = 118 MeVΓ = 21 MeV
B.E. = 87 MeVΓ = 133 MeV
KEK B.E. = 169 MeVΓ < 25 MeV
B.E. = 194 MeVΓ < 21 MeV
FINUDA B.E. =115 MeVΓ = 67 MeV
FOPI B.E. ~ 150 MeVΓ ~ 100 MeV
ppK- ppnK- pnnK-
Experimental results are more deeply bound than ours.•14% enhanced KN interaction•NN-LS interaction is important in pnnK-.
B.E. = 177 MeV
B.E. = 187 MeV
Jπ=1/2-, T=0
(0s)3
Jπ=3/2+, T=1
(0s)2(0p)
• Isobaric analog state of pppK-
• Large energy gain by KN interaction
• Additional energy gain by NN-LS interaction
Nucleon configuration of pnnK-
I=0 KN
I=1 KN
1 / 6
5 / 6
2 / 3
1 / 3
1 / 2
1 / 2
ppnK- pnnK-
(0s)3 (0s)3 (0s)2(0p)T=0 T=1
P nK-
p nK- K0
Summary of present status
Our predictions B.E. = 48 MeV
Γ = 61 MeVB.E. = 118 MeVΓ = 21 MeV
B.E. = 87 MeVΓ = 133 MeV
KEK B.E. = 169 MeVΓ < 25 MeV
B.E. = 194 MeVΓ < 21 MeV
FINUDA B.E. =115 MeVΓ = 67 MeV
FOPI B.E. ~ 150 MeVΓ ~ 100 MeV
ppK- ppnK- pnnK-
Decay width is consistent?
Summary of present status
Our predictions B.E. = 48 MeV
Γ = 61 MeVB.E. = 118 MeVΓ = 21 MeV
B.E. = 87 MeVΓ = 133 MeV
KEK B.E. = 169 MeVΓ < 25 MeV
B.E. = 194 MeVΓ < 21 MeV
FINUDA B.E. =115 MeVΓ = 67 MeV
FOPI B.E. ~ 150 MeVΓ ~ 100 MeV
ppK- ppnK- pnnK-
Consistent?Especially, decay width.
Summary of present status
Our predictions B.E. = 48 MeV
Γ = 61 MeVB.E. = 118 MeVΓ = 21 MeV
B.E. = 87 MeVΓ = 133 MeV
KEK B.E. = 169 MeVΓ < 25 MeV
B.E. = 194 MeVΓ < 21 MeV
FINUDA B.E. =115 MeVΓ = 67 MeV
FOPI B.E. ~ 150 MeVΓ ~ 100 MeV
ppK- ppnK- pnnK-
??? ?????? ???
???
Unobserved states can be found by each other experiment?
Future developmentsTheory
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
4, The study from the view point of quarks; Quark matter or not?
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
Additional attraction to
deeply bound kaonic nuclei
Future developmentsExperiment
1, More experiments to confirm the existence of kaonic nuclei
2, Determine Jπ of , especially, strange tribaryons
3, Dense or not?
Possible by measuring the momentum correlation of three particles emitted in the decay NNNK → N+N+Λ P. Kienle, Y. Akaishi and T. Yamazaki, Phys.Lett.B632, 187 (2006)
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-.
Observed strange tribaryons, ppnK- and pnnK-, can be understood …
• 14% enhanced KN interaction and NN-LS force• pnnK- : (0s)2(0p) configuration Jπ=3/2+, T=1• ppnK- : (0s)3 configuration Jπ=1/2-, T=0
Summary Various experimental results are now reported. They indicate the evidence of deeply bound kaonic nuclei.
But comparing with each other, there seems to be some inconsistency between them.
In particular in decay width.
KEK; narrow FINUDA and FOPI; broad
Need more experiments!
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