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S.N.Nakamura, Tohoku Univ.S.N.Nakamura, Tohoku Univ.
JLab HallC MeetingJLab HallC Meeting
22/Jan/2010, JLab22/Jan/2010, JLab
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)
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
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