recent progress in hypernuclear physics

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Recent Progress in Recent Progress in Hypernuclear Physi Hypernuclear Physi cs cs E. Hiyama E. Hiyama (Nara Women’s Univ.) (Nara Women’s Univ.) Hypernuclear physics has recently become v ery exciting owing to new epoch-making experimental da ta. The recent progress in hypernuclear physic s from a

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Recent Progress in Hypernuclear Physics. E. Hiyama (Nara Women ’ s Univ.). Hypernuclear physics has recently become very exciting owing to new epoch-making experimental data. The recent progress in hypernuclear physics from a theorist’s viewpoint of hypenuclear structure. - PowerPoint PPT Presentation

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Page 1: Recent Progress in Hypernuclear Physics

Recent Progress in HyperRecent Progress in Hypernuclear Physicsnuclear Physics

E. Hiyama E. Hiyama (Nara Women’s Univ.)(Nara Women’s Univ.)

Hypernuclear physics has recently become very exciting

owing to new epoch-making experimental data.

The recent progress in hypernuclear physics from a

theorist’s viewpoint of hypenuclear structure.

Page 2: Recent Progress in Hypernuclear Physics

Nuclear chart with strangenessNuclear chart with strangeness

Λ

   Outline 1. Introduction

   2. S=-1 hypernuclei and YN interactions

  3. S=-2 hypernuclei and YY interactions

  4. Future subjects

5. Concluding remarks

Multi-strangeness system such as Neutron star

Λ

Page 3: Recent Progress in Hypernuclear Physics

1. Introduction

Page 4: Recent Progress in Hypernuclear Physics

Major goals of hypernuclear physics

Fundamental and important for the studyof nuclear physics

To understand the baryon-baryon interaction, two-body scattering experiment is most useful.

YN and YY potential models so far proposed (ex. Nijmegen, Julich, Kyoto-Niigata) have large ambiguity.

1) To understand baryon-baryon interactions

2) To study the structure of multi-strangeness systems

Total number of

Nucleon (N) -Nucleon (N) data: 4,000

・ NO YY scattering data

・ Total number of differential cross section

Hyperon (Y) -Nucleon (N) data: 40

Page 5: Recent Progress in Hypernuclear Physics

Therefore, as a substitute for the 2-body limited YN and

non-existent YY scattering data,

the systematic investigation of light hypernuclear structure is

essential .

Page 6: Recent Progress in Hypernuclear Physics

Strategy to determine YN and YY interactionsfrom the studies of light hypernuclear structure

No direct information

Use Suggest to improve

Compare theoretical results with experimental data

X

Accurate calculation of hypernuclear structure Few-body, cluster model, shell model, …..

YN and YY interactions

based on meson theory: Nijmegen, Ehime, Julich ・・  based on constituent quark model: Kyoto-Niigata, ・・

Spectroscopy experiments  ・ High-resolution γ-ray spectroscopy experiment  by Tamura and his collaborators  ・ Emulsion experiment   by Nakazawa and his collaborators

My role

using a

few-body method

Page 7: Recent Progress in Hypernuclear Physics

・ A variational method using Gaussian basis functions

・ Take all the sets of Jacobi coordinates

High-precision calculations of various 3- and 4-body systems:

Our few-body caluclational method

Gaussian Expansion Method (GEM) , since 1987

Review article : E. Hiyama, M. Kamimura and Y. Kino,Prog. Part. Nucl. Phys. 51 (2003), 223.

Developed by Kyushu Univ. Group, Kamimura and his collaborators.

,

Light hypernuclei,

3-quark systems,

……….

Exotic atoms / molecules ,

3- and 4-nucleon systems,

Multi-cluster structure of light nuclei,

An example of accuracy of the method:

Page 8: Recent Progress in Hypernuclear Physics

4He

4-nucleon bound stateNN:AV8

Good agreement among the 7 different method in the binding energy, r.m.s. radius and two-body correlation function

p p

n n

Benchmark-test calculation of the 4-nucleon bound state

1. Faddeev-Yakubovski (Kamada et al.)1. Faddeev-Yakubovski (Kamada et al.)2. Gaussian Expansion Method (Kamimura and 2. Gaussian Expansion Method (Kamimura and

Hiyama)Hiyama)3. Stochastic varitional (Varga et al.)3. Stochastic varitional (Varga et al.)4. Hyperspherical variational (Viviani et al.) 4. Hyperspherical variational (Viviani et al.) 5. Green Function Variational Monte Carlo (Carl5. Green Function Variational Monte Carlo (Carl

son at al.)son at al.)6. Non-Core shell model (Navratil et al.)6. Non-Core shell model (Navratil et al.)7. Effective Interaction Hypershperical Harmonic7. Effective Interaction Hypershperical Harmonic

s (Barnea et al.)s (Barnea et al.)

PRC64, 044001(2001)

Page 9: Recent Progress in Hypernuclear Physics

Advantage New possibilities

A good example:

Our few-body calculational method (GEM)

・ Function space of the few-body

Gaussian basis functions is

so wide that they construct a complete

set in a finite region.

・ In some cases, it is not difficult to impose scattering

boundary condition on the total

few-body wavefunction

using a Kohn-type variational principle.

It becomes possible to study

spatially, highly-excited states

in few-body systems.

It becomes possible to study resonant and non-resonant continuum states of few-bodysystems in these cases.

Page 10: Recent Progress in Hypernuclear Physics

“ Five-body calculation of resonace and scattering states of pentaquark systems “

q q

q q

s +q q

q+ q

s

N K

Example of application of our method

Scattering problem of the uudds system,in the constituent quark model, was solved for the first time.

NK scattering phase shift including 5-body configurations in the finite region

    No resonance in the energy region of the reported pentaquark.

E. Hiyama, M. Kamimura, a. Hosaka, H. Toki and Y. Yahiro, E. Hiyama, M. Kamimura, a. Hosaka, H. Toki and Y. Yahiro,

Phys. Letters B633 (2006) 237.Phys. Letters B633 (2006) 237.

Page 11: Recent Progress in Hypernuclear Physics

Strategy to determine YN and YY nteractionsfrom the studies of light hypernuclear structure

Use Suggest to improve

Compare theoretical results with experimental data

Accurate calculation of hypernuclear structure Few-body, cluster model, shell model, …..

YN and YY interactions

based on meson theory: Nijmegen, Ehime, Julich ・・  based on constituent quark model: Kyoto-Niigata, ・・

Spectroscopy experiments  ・ High-resolution γ-ray spectroscopy experiment  by Tamura and his collaborators  ・ Emulsion experiment   by Nakazawa and his collaborators

2. S=-1 hypernuclei and YN interaction

3. S=-2 hypernuclei and YY interaction

Page 12: Recent Progress in Hypernuclear Physics

2. S= -1 hypernuclei 2. S= -1 hypernuclei andand

YN interactionYN interaction

Page 13: Recent Progress in Hypernuclear Physics

ΛN interaction   (effectively including ΛN -ΣN coupling)

Almost determined since 1998

----- SLS (Symmetric LS)

----- ALS (Anti symmetric LS)

One of the important issues

Page 14: Recent Progress in Hypernuclear Physics

9Be 13CΛ

0 < VALS (meson theory) << VALS (constituent quark model)

In the ALS part :

YN LS force and energy-splitting in 9Be and 13CΛ Λ

----- SLS (Symmetric LS)

----- ALS (Antisymmetric LS)

Λ

12C8Be

Λ

Λ

Nijgemen model D, F , soft core ’97a-f Kyoto-NiijataFSS potential

[vanishes in S=0 nuclei, Pauli][breaks charge symmetry]

Page 15: Recent Progress in Hypernuclear Physics

BNL-E930 BNL-E929

ΔE  LS splitting

0+

2+

8Be

Λ

1/2+

5/2+

3/2+

γ

γ

9BeΛ

(0s)

12C 13CΛ

γγ

1/2+

3/2-

1/2-

ΔEΛ

0+

(0p)

αΛ α

α

3- and 4-body calculations:E. Hiyama, M. Kamimura, T. Motoba, T. Yamada and Y. YamamotoPhys. Rev. Lett. 85 (2000) 270.

YN LS force

    1) Meson theory : Nijmegen Model D, F, soft core’97 a – f.

    2) Qurak model : Kyoto-Niigata, FSS     

αΛ

α13CΛ

9BeΛ

Page 16: Recent Progress in Hypernuclear Physics

5/2+

3/2+ 80

200keV

Meson

3/2-

1/2- 360

960keV

Meson

5/2+

3/2+35

40keV

Quark

150

200keV

Quark

~1/2-

3/2-

EXP

5/2+

3/2+

EXP keV

BNL-E930

H. Akikawa et al.Phys. Rev. Lett. 88 (2002)082501; H. Tamura et al.Nucl. Phys. A754 (2005) 58c

152

1/2-

3/2-

BNL-E929

± 54 ± 36 keVS.Ajimura et al.Phys. Rev. Lett. 86,(2001) 4255

43±5

ΛN LS force and 9Be and 13CΛ Λ

9BeΛ

13CΛ

Nijmegen model D,FSoft core ’97a-f

Page 17: Recent Progress in Hypernuclear Physics

140 ~ 250 keV

9BeΛ

SLS

5/2+

3/2+

SLS +   ALS

80 ~ 200 keV

Meson Theory

5/2+

3/2+

35 ~ 40keV3/2+

5/2+

SLS + ALS

Quark-based

We suggested that there are 2 paths to improve theMeson models : ・ reduce the SLS strength       

・ enhance the ALS strength  so as to reproduce theobserved LS splittings in 9Be and 13C.

Λ Λ

(Large) (Small)

(Large) - (Large)

LS splitting in 9BeΛ

α

Λ

α

5/2+

3/2+

Exp. keV43±5

Page 18: Recent Progress in Hypernuclear Physics

Recently, a new YN interaction based on meson theory,

extended soft core potential 06 (ESC06) by Th. A Rijken

5/2+

3/2+

39 keV

ESC06

5/2+

3/2+

EXP keV

BNL-E930

H. Akikawa et al.Phys. Rev. Lett. 88,(2002)82501;H. Tamura et al.Nucl. Phys. A754,58c(2005)

43±5

98 keV

SLSSLS + ALS

(reduced)

(small)

LS splitting in 9Be Λ

9BeΛ

Good agreement

Hiyama (2007)

Page 19: Recent Progress in Hypernuclear Physics

Strategy to determine YN and YY interactionsfrom the studies of light hypernuclear structure

Use Suggest to improve①

Accurate calculation of energy splitting (9Be and 13C)

using the YN SLS+ALS potentials

YN SLS+ALS potentials

Spectroscopy experiments   High-resolution γ-ray spectroscopy experiment in 9Be and 13C   by Tamura and his collaborators by Kishimoto and his collaborators  

comparison comparison again:good agreement

new versionpotential (ESC06)

Λ Λ

Meson theory :NijmegenQuark model :Kyoto-Niigata

Λ Λ

Page 20: Recent Progress in Hypernuclear Physics

Hypernuclear Hypernuclear -ray data since 1998-ray data since 1998

・ Millener (p-shell model),  ・ Hiyama (few-body)

Page 21: Recent Progress in Hypernuclear Physics

3. S=-2 hypernuclei 3. S=-2 hypernuclei andand

YY interactionYY interaction

Page 22: Recent Progress in Hypernuclear Physics

Λ+ ・・・・

It is conjectured that extreme limit, which includes many Λs in nuclear matter, is the core of a neutron star.

In this meaning, the sector of S=-2 nuclei ,

double Λ hypernuclei and Ξ hypernuclei is just the entrance to the multi-strangeness world.

  However, we have hardly any knowledge of the YY interaction

  because there exist no YY scattering data.Then, in order to understand the YY interaction, it is crucial to study the structure of double Λ hypernuclei and Ξ hypernuclei.

What is the structure when one or more Λs are added to a nucleus?

nucleus

ΛΛΛ

Λ

+ + +

Page 23: Recent Progress in Hypernuclear Physics

Uniquely   identified   without  ambiguity for   the first time

α+Λ+Λ

7.25 ±0.1 MeV

0+

    Recently, the epoch-making data

   has been reported by the     KEK-E373 experiment.

Observation of   6HeΛΛ

α

ΛΛ

NAGARAevent

Page 24: Recent Progress in Hypernuclear Physics

useSuggest reducing the strength of

spin-independent force by half

compare between the theoretical resultand the experimental data of the biding energy of   6He  

prediction of newdouble Λ hypernuclei

Strategy of how to determine YN and YY interactions from the study of light hypernuclear structure

YY interaction Nijmegen model D 

Λ Λ

αAccurate structure calculation

Spectroscopic experiments Emulsion experiment (KEK-E373) by Nakazawa and his collaborators

6HeΛΛ

④ ΛΛ

Page 25: Recent Progress in Hypernuclear Physics

comparison

My theoretical contributionusing few-body calculation

・ E07 “Systematic Study of double strangness systems at J-PARC” by Nakazawa and his collaborators

Approved proposal at J-PARC

Emulsion experiment Theoretical calculation

input: ΛΛ interaction to reproduce the observed binding energy of   6He

ΛΛ

identification of the state

It is difficult to determine   1) spin-parity

2) whether the observed state is the ground state or an excited state

Page 26: Recent Progress in Hypernuclear Physics

Successful example to determine spin-parity ofdouble Λ hypernucleus --- Demachi-Yanagi event for 10Be

Demachi-Yanagi event

12.33+0.35

-0.21 MeV

8Be +Λ+Λ

ground state ?excited state ?

Observation of   10Be --- KEK-E373 experiment

ΛΛ

ΛΛ

αα

Λ Λ

10BeΛΛ

10BeΛΛ

Page 27: Recent Progress in Hypernuclear Physics

4-body calculation of 10Be (Deamchi-Yanagi event)ΛΛ

VΛΛ To reproduce the   observed binding energy of 6He

ΛΛα+Λ+Λ

7.25 ±0.1 MeV

E. Hiyama, M. Kamimura, T. Motoba, T.Yamada and Y. YamamotoPhys. Rev. C66, 024007 (2002)

The binding energies of all the subsystems in 10Be are reproduced .

ΛΛ

α

ΛΛ

αα

Λ Λ

αα

Λ Λαα

Λ Λ

Page 28: Recent Progress in Hypernuclear Physics

In this way, we succeeded ininterpreting the spin-parityby comparing the experimental dataand our theoretical calculation.

Successful interplitation of spin-parity of

E. Hiyama, M. Kamimura,T.Motoba, T. Yamada and Y. YamamotoPhys. Rev. 66 (2002) , 024007

Demachi-Yanagi event

αα

Λ Λ

Page 29: Recent Progress in Hypernuclear Physics

4-body model of p-shell double Λ hypernuclei

α

Λ

x = n p d t 3He

= = = = =7He 7Li 8Li

ΛΛ ΛΛ ΛΛ8Li 9Be

ΛΛ ΛΛ

Therefore, the 4-body calculation has predictive power.

Hoping to observe new   double Λ hypernuclei in future experiments,

I have predicted level structures of these   double Λ hypernuclei

within the framework of the α+ x + Λ+Λ 4-body model.

E. Hiyama, M. Kamimura, T. Motoba, T.Yamada and Y. YamamotoPhys. Rev. C66, 024007 (2002)

Page 30: Recent Progress in Hypernuclear Physics

Spectroscopy of ΛΛ-hypernuclei E. Hiyama, M. Kamimura,T.Motoba, T. Yamada and Y. YamamotoPhys. Rev. 66 (2002) , 024007

By comparing this theoretical prediction and future experimental data, we can interpret the spectroscopy of those double Λ hypernuclei.

Page 31: Recent Progress in Hypernuclear Physics

4. Future subjects4. Future subjects

Page 32: Recent Progress in Hypernuclear Physics

In S=-1 sector, what are the open questions in   YN interaction?

(1) Charge symmetry breaking

(2) ΛN - ΣN coupling

(1) E13 at J-PARC “γ-ray spectroscopy of light hypernuclei”

by Tamura and his collaborators

Day-1 experiment 11B 4HeΛ Λ

(2) E10 at J-PARC “Study on Λ-hypernuclei with the double Charge-Exchange reaction”

by Sakaguchi , Fukuda and his collaboratiors

Parallel session ( E3-1 )6th June, 14:30 ~Room:G510

9HeΛ

6HΛ

Page 33: Recent Progress in Hypernuclear Physics

In S=-2 sector, the most important subjects still to be studied

(1)  ΛΛ - ΞN coupling

(2)   ΞN -ΞN interaction

I shall introduce above two subjects.

Page 34: Recent Progress in Hypernuclear Physics

One of the major goals in hypernuclear physics :

To study structure of multi-strangeness systems

(extreme limit : neutron star)

NN

N N

Λ ΛΛΛΛ

N

N

N Multi-strangeness systems

25MeVΛΛ

ΞN

Threshold energy difference is very small ! It is considered that

ΛΛ→ΞN particle conversion is strong in multi-strangeness systems.  

(1) ΛΛ - ΞN coupling

Page 35: Recent Progress in Hypernuclear Physics

S1/2

P3/2

n n p p Λ Λ Ξ-

PauliForbidden

 ・ I.R. Afnan and B.F. Gibson, Phys. Rev. C67, 017001 (2003).

・ Khin Swe Myint, S. Shinmura and Y. Akaishi, nucl-th/029090.

・ T. Yamada and C. Nakamoto, Phys. Rev.C62, 034319 (2000).

p

6HeΛΛ

V ΛΛ--ΞN

(3 protons in S1/2)

Effect of ΛΛ - ΞN coupling is small in   6He which was observed as NAGARA event.

ΛΛ

Page 36: Recent Progress in Hypernuclear Physics

4H 5H ( 5He)ΛΛ

・ I.N. Filikhin and A. Gal, Phys. Rev. Lett. 89, 172502   (2002)

・ Khin Swe Myint, S. Shinmura and Y. Akaishi, Eur. Phys. J.   A16, 21  (2003).

・ D. E. Lanscoy and Y. Yamamoto, Phys. Rev. C69, 014303   (2004).

・ H. Nemura, S. Shinmura, Y. Akaishi and Khin Swe Myint,   Phys. Rev. Lett. 94, 202502 (2005).

Λ Λ

nn

ΛΛ

Λ Λ

pnΛΛ

For the study of ΛΛ - ΞN coupling interaction,

s-shell double Λ hypernuclei such as

4H and 5H ( 5He) are very suitable.ΛΛ ΛΛ ΛΛ

p

Page 37: Recent Progress in Hypernuclear Physics

S1/2

P3/2

5HΛΛ

n n p Λ Λ Ξ- p

5HΛΛ

V ΛΛ - ΞN

(2 protons in S1/2)

Due to NO Pauli plocking, the ΛΛ - ΞN coupling can be large in 5H

ΛΛ

B.F. Gibson, I.R. Afnan, J.A.Carlson and D.R.Lehman,Prog. Theor. Phys. Suppl. 117, 339 (1994).

Λ Λ

nn

p

Page 38: Recent Progress in Hypernuclear Physics

The detailed studies will be reported by

・ D. Lanskoy ( E3-7 )

・ Y. Yamamoto ( E4-2 )

・ H. Nemura ( E4-5 )

6th June, afternoon, 14:30 ~ 18:30 “Hyperon Interactions and Hypernuclear Physics” Room: G510

In this way, the study of structure of s-shell double Λ hypernuclei is important for the study of ΛΛ ー ΞN coupling.

Page 39: Recent Progress in Hypernuclear Physics

For the study of ΞN interaction, it is important to study

the structure of Ξ hypernuclei.

However, so far there was no observed Ξ hypernuclei.

Then, it is important to predict theoretically what kinds of

Ξ hypernuclei will exist as bound states.

nucleus

Ξ Ξ hypernucleus

In S=-2 fields, the most important subjects to be still studied

(2) ΞN -ΞN interaction

Page 40: Recent Progress in Hypernuclear Physics

For this purpose, recently, I studied these Ξ hypernuclei.

(d+Ξ-)

α

ΞN interaction to reproduce the experimental data of 12C(K-,K+) reaction  ・ T. Fukuda et al. Phys. Rev. C58, 1306, (1998);   ・ P.Khaustov et al. Phys. Rev. C61, 054603 (2000).

(ESC04)

Ξ-

Ξ- Ξ-n

Ξ- αpn np

(t +Ξ-)-(

p

n n

( 5 Li+Ξ-)

(6He+Ξ-)

Ξ-

α α

Ξ- t

α α

n

(9Be+Ξ-) (11B+Ξ-)

-

Page 41: Recent Progress in Hypernuclear Physics

Spectroscopy of Ξ hypernuclei at J-PARC

(pn+Ξ ) (pnn+Ξ )

-2 d+Ξ

t +Ξ

1/2 +

0+

1+

αn+Ξ

2-

1-(α+Ξ)+nn

1/2+

(8Be+Ξ)+n

2-

11B+Ξ

1-

1-

2-

(5He+Ξ) (6He+Ξ) ( 9 B e+Ξ) (11B+Ξ)

Ξ- t

α αΞ- n

α ααΞ-

n nn

Ξ-α

Ξ-n n

pp

Ξ-n

-5

0

-10

MeV

-20

Page 42: Recent Progress in Hypernuclear Physics

11B

pK-

Ξ-

11B

12C Ξ hypernucleus

・ E05 “Spectroscopic study of Ξ-Hypernucleus, 12Be, via the 12C(K-,K+)

Reaction” by Nagae   and his collaboratorsDay-1 experiment

First observation of Ξ hypernucleus

K+

Approved proposal at J-PARC

This observation will give information about ΞN   interaction.

Page 43: Recent Progress in Hypernuclear Physics

Spectroscopy of Ξ hypernuclei at J-PARC

(pn +Ξ) (pnn+Ξ)

-2 d+Ξ

t +Ξ

1/2 +

0+

1+

αn+Ξ

2-

1-(α+Ξ)+nn

1/2+

(8Be+Ξ) +n

2-

11B+ Ξ

1-

1-

2-

(5He+Ξ) (6He+Ξ) ( 9 Be+Ξ) (11B+Ξ )

Ξ- t

α αΞ- n

α ααΞ-

n nn

Ξ-α

Ξ-n n

pp

Ξ-n

-5

0

-10

MeV

-20

Page 44: Recent Progress in Hypernuclear Physics

Multi-strangeness systemsuch as Neutron star

J-PARC

Concluding remark

GSIJLABDAΨN EJ-PARC

Page 45: Recent Progress in Hypernuclear Physics

At the end of next year (2008), the first beam in the main ring will appear at J-PARC.

And, it is planned to perform the first experiment onhypernuclei in early 2009.

So, it is expected that all hypernuclear experimentalists may be very busy.

If man-power for such experiments is not enough,

I am ready to join those experiments.

Page 46: Recent Progress in Hypernuclear Physics

In 2002, KEK-E509,

I had 7 shifts for this experiment.

Film badge

Page 47: Recent Progress in Hypernuclear Physics

I shall be happy if I could join the future experiments

at J-PARC facility with this new film badge.

New film badge

01 / 2009

Page 48: Recent Progress in Hypernuclear Physics

Thank you!