S.N.Nakamura, Tohoku Univ.S.N.Nakamura, Tohoku Univ.

JLab HallC MeetingJLab HallC Meeting

22/Jan/2010, JLab22/Jan/2010, JLab

AZp A

(Z-1)

Hypernuclei in wide mass rangeHypernuclei in wide mass range

Medium - Heavy hypernuclei

Neutron/Hyperon star

Light Hypernuclei (s,p shell)

A 1 20 50 200 1057

Elementary Process

Strangeness electro-production

Fine structure Baryon-baryon interaction in SU(3) coupling in large isospin hypernuclei Cluster structure

Hyperonization Softening of EOS ?

Superfluidity

Single-particle potentialDistinguishability of a hyperon

U0(r), m*(r), VNN, ...

E89-009 12C

E01-011 7Li 12C 28Si

Neutron/Hyperon star, Strangeness matter

E94-107

9Be 12C 16O

Shell model

Bare N Int.Few body calc. Mean Field TheoryCluster calc.

1212C (e,e’K) C (e,e’K) 1212BB

Calibration and Reference spectrumCalibration and Reference spectrum

PreliminaryPreliminaryJLAB – HKSJLAB – HKSs(2

-/1-)

p

C.E. #1 (1-)

C.E. #2(2-/1-)

AccidentalsAccidentals

B (MeV)

Co

un

t s

/ 0.

15 M

eV

　 gs　resolution:　465　keV　(FWHM)

KEK E369 (2001) 1212C (C (,K) ,K) 1212CC

FWHM~1.5 MeV

JLab E94-107 (2004) Hall A

12B

Excitation Energy(MeV)

Counts /0.2 MeV FWHM~670keV

77Li target :Li target :Physics of (A = 7,T=1)Physics of (A = 7,T=1)E. Hiyama et al.PRC80,054321(2009)

-5.40 (EXP)

-3.79 (EXP)

Possible Charge Sym. Breaking?

NO Reliable DATA

-4.42

(T=1)

-6.39

-5.40

BΛ=-5.58

7L

i

7He

7B

e

αΛ

n n

αΛ

n p

αΛ p

p

M.Jurič et al., NP B52(1973) 1

77Li(e,e’KLi(e,e’K++))77HeHe

J -B　[MeV]

Cross　section　[nb/sr]

SLA C4 KMAID

1/2+ -5.37 13.2 16.2 9.7

Theoretical calculation Binding energy: Hiyama w/o CSB Cross section: Sotona et.al.(1.3 < E < 1.6 GeV, 1 < qK < 13 deg.)

Preliminary result

ID -B

[MeV]

Cross　section　[nb/sr]

#1 -5.7±0.2　(stat.)

　　　　　　　±0.2　(sys.)

15±3　(stat.)

　　　±3　(sys.)

#1

Resolution　:　~510　keV　(FWHM)　for　g.s.Data　taking　:　~30　hours　w/　30　A

77Li target :Physics of (A = Li target :Physics of (A = 7,T=1)7,T=1)

E. Hiyama et al.PRC80,054321(2009)

7Li(e,e’K+)

-5.40 (EXP)

-3.79 (EXP)

Possible Charge Sym. Breaking?-4.42

-4.42

(T=1)

-6.39

-5.40

-6.70.2 0.2 (E01-011 Preliminary)

77HeHe

α

n

n

Λ

α

Unbound neutron halo

Bound states

Direct Observation of ’s glue-like role

n

n

NO DATA

Another Physics of Another Physics of HKS-HES (E05-115)

2828Si(e,e’KSi(e,e’K++))2828Al – First Spectroscopy of Al – First Spectroscopy of 2828

AlAl　

PreliminaryPreliminary

S

p dC

ou

nts

/ 0.

15 M

eV

B- Binding Energy (MeV)

JLAB – HKS JLAB – HKS

AccidentalsAccidentals

g.s. resolution ~420 keV

KEK E140a (1995)28

Si

GatewayGateway to hypernuclear spectroscopy in the medium-heavy mass region

Enriched 28Si target100 mg/cm2

30A electron beam

Natural Si target2000 mg/cm2

106/sec + beam

28Al

2828Si(e,e’KSi(e,e’K++))2828Al – First Spectroscopy of Al – First Spectroscopy of 2828

AlAl　

PreliminaryPreliminary

S

p dC

ou

nts

/ 0.

15 M

eV

B- Binding Energy (MeV)

JLAB – HKS JLAB – HKS

AccidentalsAccidentals

g.s. resolution ~420 keV

GatewayGateway to hypernuclear spectroscopy in the medium-heavy mass region

Enriched 28Si target0.1 g/cm2

30A electron beam28Al

Motoba et al.Full shell model calc.[s4p12(sd)12] space

E05-115 HKS-HESE05-115 HKS-HESthe 3the 3rdrd generation (e,e generation (e,e’’KK++) hypernuclear ) hypernuclear spectroscopyspectroscopyAug. ~ Oct. 2009Aug. ~ Oct. 2009

Medium - heavy hypernuclear spectroscopy

52Cr(e,e’K+) 52V

hyperon bound in the mean field

quark picture vs. conventional picture

Light hypernuclear spectroscopy

N interaction, ls coupling, Charge Symmetry Breaking

p shell hypernuclei 7Li, 9Be,10B, 12C, 16O targets

Calibration and study of the elementary process

proton : H2O and CH2

Introduction of newly developed HES (High-resolution Electron Spectrometer)

PreChicane-SPL-(HKS+HES) PreChicane-SPL-(HKS+HES) ConfigurationConfiguration

SPL : One entrance, Four SPL : One entrance, Four exits!exits!

Hypernuclei in wide mass rangeHypernuclei in wide mass range

Neutron/Hyperon star, Strangeness matter

Light Hypernuclei (s,p shell)

A 1 20 50 200 1057

Elementary Process

Strangeness electro-production

Fine structure Baryon-baryon interaction in SU(3) coupling in large isospin hypernuclei Cluster structure

Hyperonization Softening of EOS ?

Superfluidity

E05-1151H 7Li 9Be 10B 12C 52Cr

Single-particle potentialDistinguishability of a hyperon

U0(r), m*(r), VNN, ...

Medium - Heavy hypernuclei

3rd Gen. Exp.

Bare N Int.Few body calc. Mean Field TheoryCluster calc.

Shell model

1010B targetB targetMillener’s parameterization(V,D,SN,S,T)

Hyperball’s data

α α

n Λ

10BeΛ

α α

p Λ

10BΛ

Imperfect treatment of Tensor force?Bad wavefunction of the core nucleus?

predicts >200keV 1-2- separation

10B(e,e’K)

Cluster Calc. based on the same framework

Calibration RunCalibration Run

Mx-M [MeV]

Count[/MeV]

Missing Mass spectrum

HKS-HES coin time spectrum

ns

count

True+Acc.

Acc

HES mom [GeV/c]

HKS mom [GeV/c]

Width of ~4MeV (FWHM)

Good Coincidence!

1212C Target Data (w/ untuned C Target Data (w/ untuned matrices) matrices)

-B [MeV]

Count[/MeV]

g.s?

P-shell?

Target Number of Quasi-Free (observed)

Quasi-Free Cross Section (assumed)

Hypernuclei (g.s)Cross Section(assumed)

Expected number of g.s

7Li 6.4　x104 1.0　b/sr 21　nb/sr 1300

9Be 4.5　x104 1.2　b/sr 4　nb/sr 150

10B 4.8　x104 1.3　b/sr 21　nb/sr 780

12C 3.4　x104 1.5　b/sr 112　nb/sr 2500

52Cr 1.4　x104 4.7　b/sr 69　nb/sr 210

• Cross section of QF is assumed as 0.2*A0.8 [b/sr]• # of g.s is calculated as (# of )*(g.s cross section)/(QF cross section)• Cross Section of 9Be is derived by Progress of Theoretical Physics Supplement No.117 (1994) pp. 151-175 (M. Sotona and S. Frullani) and other cross sections are summarized in E05-115 experiment proposal (JLab PAC 28 and 33).

SummarySummary

With　a　high　quality　electron　beam　from　CEBAF,　　　　　　(e,e’K)　hypernuclear　spectroscopy　was　established The　second　gen.　exp.　E01-011　(HKS)　achieved　<500keV　

(FWHM)　resolution　　12

B　　:　s　width　problem　solved　　　　7

He　:　first　reliable　observation　of　g.s.,　CSB　　　28

Al　:　first　observation,　doorway　to　mid-heavy　HY The　third　gen.　exp.　E05-115　(HKS-HES)　successfully　finishedCalibration,　Elementary　Process　　　　　　7

He　:　CSB,　　glue-like　role　　　　　　9

Li　　　:　p-shell　Hy　　　　　　10

Be　:　CSB,　Tensor　force,　Sheds　light　on　10B　problem

　　　　12B　:　Reference　data　&　core　excited　states

　　　　52V　:　First　mid-heavy　HY　data,　core-config.　mixing,　ls-force

Final Check of AnalysisPreparing for publication

Preparing mass production of1st condensed data set