Transcript S.N.Nakamura, Tohoku Univ. JLab HallC Meeting 22/Jan/2010, JLab AZ p A L(Z-1) Hypernuclei in wide mass range A E89-009 E94-107 12C 9Be 12C 16O E01-011 Elementary Process 7Li 12C 28Si Strangeness electro-production Light Hypernuclei (s,p shell) Fine.

S.N.Nakamura, Tohoku Univ.
JLab HallC Meeting
22/Jan/2010, JLab
AZ
p
A
L(Z-1)
Hypernuclei in wide mass range
A
1
E89-009
E94-107 12C
20
50
200
1057
9Be 12C 16O
E01-011
Elementary Process
7Li
12C
28Si
Strangeness electro-production
Light Hypernuclei (s,p shell)
Fine structure
Baryon-baryon interaction in SU(3)
LS coupling in large isospin hypernuclei
Cluster structure
Neutron/Hyperon star,
star
Strangeness matter
Hyperonization 
Softening of EOS ?
Superfluidity
Medium - Heavy hypernuclei
Single-particle potential
Distinguishability of a L hyperon
U0(r), mL*(r), VLNN, ...
Shell model
Bare LN Int. Few body calc.
Cluster calc.
Mean Field Theory
12C
(e,e’K) 12LB
Calibration and Reference spectrum
gs resolution: 465 keV (FWHM)
sL(2-/1-)
JLAB – HKS
Count s / 0.15 MeV
pL
C.E. #1 (1-)
C.E. #2(2-/1-)
Counts /0.2 MeV
Preliminary
JLab E94-107 (2004) Hall A
BL (MeV)
FWHM~1.5 MeV
12
LB
Excitation Energy(MeV)
Accidentals
KEK E369 (2001)
FWHM~670keV
12C
(p,K) 12LC
7Li
target :Physics of (A = 7,T=1)
E. Hiyama et al.
PRC80,054321(2009)
M.Jurič et al., NP B52(1973) 1
7 Be
L
BΛ=-5.58
-3.79 (EXP)
7 Li
L
-4.42
Possible Charge Sym. Breaking?
-5.40 (EXP)
Λ
NO Reliable DATA
-5.40
α
Λ
7 He
L
n p
α
-6.39
Λ
n n
α
p
(T=1)
p
7Li(e,e’K+)7
LHe
Preliminary result
ID
-BL
[MeV]
Cross section
[nb/sr]
#1
-5.7±0.2 (stat.)
±0.2 (sys.)
15±3 (stat.)
±3 (sys.)
#1
Theoretical calculation
Binding energy: Hiyama w/o CSB
Cross section: Sotona et.al.
(1.3 < Eg < 1.6 GeV, 1 < qK < 13 deg.)
Jp
Resolution : ~510 keV (FWHM) for g.s.
Data taking : ~30 hours w/ 30 mA
1/2+
-BL
[MeV]
Cross section [nb/sr]
SLA
C4
KMAID
-5.37
13.2
16.2
9.7
7Li
Hiyama et al.
target :Physics of (A = 7,T=1) E.PRC80,054321(2009)
-3.79 (EXP)
-4.42
-5.40 (EXP)
Possible Charge Sym. Breaking?
-4.42
-5.40
-6.39
7Li(e,e’K+)
-6.70.2 0.2 (E01-011 Preliminary)
(T=1)
Another Physics of
7 He
L
HKS-HES (E05-115)
n
Unbound neutron halo
NO DATA
α
Λ
n
Bound states
n
α
S
n
Direct Observation of L’s glue-like role
28Si(e,e’K+)28
28 Al
Al
–
First
Spectroscopy
of
L
L
Gateway to hypernuclear spectroscopy in the medium-heavy mass region
JLAB – HKS
Preliminary
28
LAl
Counts / 0.15 MeV
g.s. resolution ~420 keV pL
SL
Enriched 28Si target
100 mg/cm2
30mA electron beam
Accidentals
BL- Binding Energy (MeV)
28
LSi
dL
KEK E140a (1995)
Natural Si target
2000 mg/cm2
106/sec p+ beam
28Si(e,e’K+)28
28 Al
Al
–
First
Spectroscopy
of
L
L
Gateway to hypernuclear spectroscopy in the medium-heavy mass region
JLAB – HKS
Preliminary
28
LAl
Counts / 0.15 MeV
g.s. resolution ~420 keV pL
dL
SL
Enriched 28Si target
0.1 g/cm2
30mA electron beam
Accidentals
BL- Binding Energy (MeV)
Motoba et al.
Full shell model calc.
[s4p12(sd)12] space
E05-115 HKS-HES
the 3rd generation (e,e’K+) hypernuclear spectroscopy
Aug. ~ Oct. 2009

Medium - heavy hypernuclear spectroscopy
52Cr(e,e’K+) 52 V
L


Lhyperon bound in the mean field

quark picture vs. conventional picture
Light L hypernuclear spectroscopy

LN 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)
Configuration
SPL : One entrance, Four exits!
Hypernuclei in wide mass range
A
1
E05-115
1H 7Li 9Be 10B 12C
20
Elementary Process
50
200
1057
52Cr
Strangeness electro-production
Light Hypernuclei (s,p shell)
Fine structure
Baryon-baryon interaction in SU(3)
LS coupling in large isospin hypernuclei
Cluster structure
Neutron/Hyperon star,
Strangeness matter
Hyperonization 
Softening of EOS ?
Superfluidity
Medium - Heavy hypernuclei
Single-particle potential
Distinguishability of a L hyperon
U0(r), mL*(r), VLNN, ...
3rd Gen. Exp.
Shell model
Bare LN Int. Few body calc.
Cluster calc.
Mean Field Theory
10B
target
Millener’s parameterization(V,D,SN,SL,T)
Hyperball’s g data
predicts >200keV 1-2- separation
10B(e,e’K) 10Be
Λ
10B
Λ
n
α
Λ
α
p
Λ
α
α
Cluster Calc. based on the same framework
Imperfect treatment of Tensor force?
Bad wavefunction of the core nucleus?
Calibration Run
Missing Mass spectrum
Count
[/MeV]
L
Width of L
~4MeV (FWHM)
S0
Good Coincidence!
Mx-ML [MeV]
count HKS-HES coin time spectrum
HES mom [GeV/c]
L
True+Acc.
Acc
S0
ns
HKS mom [GeV/c]
12C
Target Data (w/ untuned matrices)
P-shell?
g.s?
Count
[/MeV]
-BL [MeV]
•
Target
Number of
Quasi-Free L
Quasi-Free L Cross Section
(observed)
(assumed)
7Li
6.4 x104
9Be
Hypernuclei
(g.s)
Cross Section
(assumed)
Expected
number of g.s
1.0 mb/sr
21 nb/sr
1300
4.5 x104
1.2 mb/sr
4 nb/sr
150
10B
4.8 x104
1.3 mb/sr
21 nb/sr
780
12C
3.4 x104
1.5 mb/sr
112 nb/sr
2500
52Cr
1.4 x104
4.7 mb/sr
69 nb/sr
210
Cross section of QF L is assumed as 0.2*A0.8 [mb/sr]
• # of g.s is calculated as (# of L)*(g.s cross section)/(QF L 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).
Summary
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
Final Check of Analysis
12 B : s width problem solved
L
L
Preparing for publication
7 He : first reliable observation of g.s., CSB
L
28 Al : first observation, doorway to mid-heavy HY
L
 The third gen. exp. E05-115 (HKS-HES) successfully finished
L:Calibration, Elementary Process
7 He : CSB, L glue-like role
Preparing mass production of
L
1st condensed data set
9 Li : p-shell Hy
L
10 Be : CSB, Tensor force, Sheds light on 10 B problem
L
L
12 B : Reference data & core excited states
L
52 V : First mid-heavy HY data, core-config. mixing, ls-force
L
