Three- and four-body structure of S=-2 hypernucleiE. Hiyama (Nara Womens Univ.)

nuclei+Hyperon()=>HypernucleiTo study 3- and 4-body structure of light hypernuclei consisting of nucleus and hyperon

At Japan Proton Accelerator Research Complex(J-PARC), they are planning to produce

(1) Many double hypernuclei

(2)Many hypernuclei

Here, I shall discuss these subjects.I also discuss what is interesting and important to studydouble hypernuclei and hypernuclei.

nucleinuclei

The purpose of my talk

(1)To predict level structure of many double hypernuclei

NpdHeHeLiLiLiBeBeNNNNNN(2)To predict level structure hypernucleus

Why is it important to produce many double and hypernuclei?

Answer Since there are NO hyperon(Y)-hyperon(Y) scattering data, YY interaction so far proposed have a large degree of ambiguity.

In order to understand YY interaction, we need YY scattering data.However, even at J-PARC facility, it is very difficult to perform YY scattering experiment.

Therefore, it is very important to obtain information aboutYY interaction from the spectroscopy experiments of many double and hypernuclei.

My contribution To understand the hypernuclear structure by performing our three- and four-body calculations and to use this structure information to understand the YN and YY interactions

The purpose of my talk

(1)To predict level structure of many double hypernuclei

NpdHeHeLiLiLiBeBeNNNNNN(2)To predict level structure of hypernucleus

Up to now, there was NO experimental data aboutdouble hypernuclei with NO ambiguity.

Two epoch-making data have been reported by theKEK-E373 experiment.

(1) Observation of 6HeUniquely identified without ambiguity forthe first time++7.25 0.1 MeV0+NAGARA Event

(2) Observation of 10Be12.33+0.35-0.21MeV8Be++Deamchi-Yanagi eventground state ?excited state?

Two important issues:Does the interaction which is designed to reproduce the binding energy of 6He reproduce the Demachi-Yanagi event for 10Be consistently?(2) When we use the same interaction, how is theoretical prediction of level structure of other double hypernuclei?

Two important issues:Does the interaction which is designed to reproduce the binding energy of 6He reproduce the Demachi-Yanagi event for 10Be consistently?(2) When we use the same interaction, how is theoretical prediction of level structure of other double hypernuclei?

10Be

KEK-E373 Demachi- Yanagi event

Our 4-body calculation is predictive.Therefore, hoping to observe many doublehypernuclei in the future experiment at J-PARC, I predict level structure of double hypernuclei.

xx=Npdt3He=====7He7Li8Li8Li9Be3N5H, 5Henp4H

Two important issues:Does the interaction which is designed to reproduce the binding energy of 6He reproduce the Demachi-Yanagi event for 10Be consistently?(2) When we use the same interaction, how is theoretical prediction of level structure of other double hypernuclei?

Spectroscopy of -hypernucleiprediction-3.385He4H

In the s-shell hypernuclei, new component of interactionshould be taken into account.

A missing component isN coupling.

A missing component is N component.nucleiV N=>nucleiNconvertintoDouble hypernuclei

Non-strangeness nucleiNNNN250MeVProbability of in nuclei is not large.25MeVNThere is significant probabilityof in double hypernuclei.

In hypernuclear physis, it is fashionable subject to investigate N coupling mechanism in double hypernuclei.

4H is very suitable hypernucleus to get information on -N coupling interaction.Up to now, there is NO experimental data about 4H.np4HThe important issue: Does the YY interaction which designed to reproduce the binding energy of 6He make 4H bound?And how does the effect of N coupling play important role in the binding energy of 6He and 4H?

1)I.N. Filikhin and A. Gal, Phys. Rev. Lett. 89, 172502(2002)2)H. Nemura, Y. Akaishi et al., Phys. Rev. C67, 051001(2002)

npVNOT BOUND !4H6HeNAGARA event++7.250.1 MeV0+

Did not include -N coupling-Ncoupling => significant in 4Hnp4HNot so important in 6He6He

S1/2P3/26HennppnForbiddenThe effect of -N coupling is small in 6He and thep-shell double hypernuclei 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).V N

S1/2npn4HP3/2allowed(- p)There is NO Pauli blocking and the N effectcan be large.

npNNN+4HOne of the most numerically difficult 4-body problemE. HiyamaDr. Nemurannnn

E(MeV)0-3.12-7.250+ Exp.(KEK-E373)CAL.5He+++6Hewith Pauli blockingE(MeV)n+p++3H+NoExp.unboundNNchannel only NN+NNNP=1.6%4H with no Pauli blocking0MeV

It is possible that N coupling potential makes the lightest double hypernucleus, 4H bound.If the bound state of 4H is observed at J-PARC,we can obtain useful information on N couplingmechanism.

Outline of my talk

(2) To predict level structure of hypernucleus

NNNNNN

028MeVNNN4HE(MeV)

So far, there was NO experimental data about hypernuclei.

To produce hypernuclei is one of main experimental project at J-PARC.

Therefore, it is requested to predict what kind of hypernuclei exist as bound states theoretically.

And also it is requested to suggest what part of N interaction we can determine from structure of hypernuclei.

NNNNNNThe strategy of this study

(1)I should perform 4-body calculation using realistic force directly.

(2) Although we cannot predict the level structure of NNN hypernucleus due to the large degree of ambiguity of N interaction, we can investigate what part of N interaction contribute to the binding energy of this hypernucleus.

(3)If this hypernucleus will be observed in the future at J-PARC, we can suggest how to improve the realistic force directly form the structure study side.

YY interaction: Extended soft core potential 04 (ESC04) proposed by Nijmegen group

Nijmegen soft core 97 e and f (NSC97e and f)

Results ESC04(3N)+0 MeV0+1+-2.3-0.86NNNNNNNN1+: [12V(1,1)+V(1,0)+10V(0,1)+3V(0,0)]/260+:[V(1,0)+V(0,1)]/2T,S==repulsivestrongly attractive repulsiveweakly repulsivestrongly attractive

Results 3N+3N+unboundunboundNSC97eNSC97fNNNNNN

If the NNN state is observed as a bound state in thefuture, we can extract information on N interaction.Therefore, I hope to perform search-experiment of thishypernucleus.

Spectroscopy of -hypernucleiprediction

28MeV6He7He7Li8Li9Li9Be10Be +x+N+???????Spectroscopy of hypernuclei at J-PARCxN=n,p,d,t,3He,

My future study plan

The study of structure of p-shell hypernucleibased on +x++N 4-body model.

n,p,d,t,3He,

N

Conclusion

(1)To predict level structure of many double hypernuclei

NpdHeHeLiLiLiBeBeNNNNNN(2)To predict hypernucleus

6He10BeS=-2S=0NNI hope that J-PARC project will produce many double hypernuclei. S=-1Schematic illustration of the nuclear chartIn this way, I hope that J-PARC project give an importantcontribution to extending the strangeness nuclear chart.They will observe hypernuclei for the first time at J-PARC.