1. HYPERNUCLEAR PHYSICS - N interaction
Perspectives of Hypernuclear Physics at Jlab in the 12 GeV era
F. Garibaldi on behalf of Jlab hypernuclear collaboration
HYPERNUCLEAR PHYSICS
Hypernuclei are bound states of nucleons with a strange baryon (L hyperon).
Extension of physics on N-N interaction to system with S≠0
Internal nuclear shells
are not Pauli-blocked
for hyperons
Spectroscopy
Few-body aspects and YN, YY interaction
Mean field aspects of nuclear matter
Astrophysical aspect
- N interaction
L-N force vs N-N force will provide clues to the QCD description of the N-N Force (one-p and one-r exchange suppressed)
many body problems

2. Hypernuclear Spectroscopy
L N interaction
(r)
✔ most of information is carried by the spin
dependent part
✔ doublet splitting is determined by D, sL, T

3. new aspects of hyernuclear structure
production of mirror hypernuclei  Charge Symmetry Breaking ?

4. Hall A Kaon collaboration
F.Garibaldi (INFN), S. Frullani (INFN). M.Iodice (INFN), J.LeRose (Jlab), P. Markowitz (FIU),G. Chang (Maryland)
E E E
96 collaborators - 30 Institutions,

5. Hall C hardware contribution

6. Hall A deector setup RICH Detector hadron arm
aerogel first generation
RICH Detector
hadron arm
aerogel second generation
septum magnets
electron arm
To be added to do the experiment

7. ✓ p(e,e′K+)L/S The data suggest that not only do the present models fail to describe the data over the full angular range, but that the cross section rises at the forward angles. The failure of existing models to describe the data suggests the reaction mechanisms may be incomplete.
✓ 7Li(e,e’k) 7LHe A clear peak of the 7He ground state for the first time. CSB term puzzle, (CSB term is essential for A=4 hypernuclei).  our understanding of the CSB effect in the N L interaction potential is still imperfect.
✓ 9Be(e,e’K+)9LLi: Disagreement between the standard model of p-shell hypernculei and the measurements, both for the position of the peaks and for the cross section.
✓ 12C(e,e’K+) 12LB: for the first time a measurable strength with sub-MeV energy resolution has been observed in the core-excited part of the spectrum. The s part of the spectrum is well reproduced by the theory, the p shell part isn’t.
✓.16O(e,e’K+)16LN: The fourth peak ( in p state) position disagrees with theory. This might be an indication of a large spin-orbit term SL. Binding Energy BL=13.76±0.16 MeV measured for the first time with this level of accuracy

8. Hypernuclei in a wide mass range Hyperonization Softening of EOS ?1 E 20 50
200
1057 A
E05-115
6,7Li ,11B 12C V 52Cr 89Y
208Pb
Elementary Process
Neutron/Hyperon star Strangeness matter
Strangeness electro-production
Light Hypernuclei (s,p shell)
Hyperonization Softening of EOS ?
Superfluidity
Fine structure
Baryon-baryon interaction in SU(3)
LS coupling in large isospin hypernuclei
Cluster structure
Medium - Heavy hypernuclei
Single-particle potential
Distinguishability of a L hyperon
U0(r), mL*(r), VLNN, ...
Shell model
Bare LN Int.
Few body calc.
Mean Field Theory
Cluster calc.

9. Decay Pion Spectroscopy to Study -Hypernuclei
Direct Production p e’ e
12C
K +
Example: 
Hypernuclear States:
Λs (or Λp) coupled to low lying core nucleus 1-
0.0 2-
~150 keV
Ground state doublet of 12ΛB
Precise BΛ
Jp and  γ* 
12ΛBg.s.
E.M. 
12ΛB
12C
 -
Weak mesonic two body decay
( -  0.1)
Weak 2 body mesonic decay at rest uniquely connects the decay pion momentum to the well known structure of the decay nucleus, B and spin-parity of the ground state of hyperfragment

11. Summary and outlook
Hypernuclear Spectroscopy by e.m. probe successfully established at Jlab confirming its excellence for studying hypernuclei
The experiments required important, challenging modifications to the Hall A and Hall C detector setup
Crucial contributions from Italian and Japanese collaborations
The new equipment performed excellently.
Best characteristics of Hall A and Hall C detectors setup understood
Merging collaborations and getting the best out of the two detectors
in order to best continue into the 12 GeV era
Jlab beam and detectors make it unique in the international panorama for this physics

12. backup

13. YN, YY Interactions and Hypernuclear Structure
Free YN, YY interaction
Constructed from limited hyperon scattering data
(Meson exchange model: Nijmegen, Julich)
G-matrix calculation
YN, YY effective interaction in finite nuclei
(YN G potential)
Hypernuclear properties, spectroscopic information
from structure calculation (shell model, cluster model…)
Energy levels, Energy splitting, cross sections
Polarizations, weak decay widths
high quality (high resolution & high statistics) spectroscopy plays a significant role

16. H.-J. Schulze, T. Rijken PHYSICAL REVIEW C 84, 035801 (2011)

17. Understanding the N-N Force
In terms of mesons and nucleons:
Or in terms of quarks and gluons:
V =

18. Hypernuclei Provide Essential Clues
For the N-N System:
For the L-N System:

19. Hypernuclei Provide Essential Clues
For the N-N System:
For the L-N System: Long Range Terms Suppressed (by Isospin)

20. L single particle energies
E (HKS-HES)
E01-011(HKS)
E94-107
(Hall A HY)
Calculation by John Millener, using a Woods-Saxon potential with a depth of 28 MeV and a radius parameter of A-2/3

21. An example of what we learn from Hypernuclei
A Highlight of JLab E (HKS)
The First reliable observation of 7LHe
A Test of Charge Symmetry Breaking
Begin with a theoretical description of these nuclei without CSB

22. An example of what we learn from Hypernuclei
A Highlight of JLab E (HKS)
The First reliable observation of 7LHe
A Test of Charge Symmetry Breaking
Begin with a theoretical description of these nuclei without CSB
A Naïve calculation of the CSB effect, which explains 4LH –4LHe and available s, p-shell hypernuclear data, predicts opposite shifts for A=7 ,T=1 iso-triplet L Hypernuclei.

23. An example of what we learn from Hypernuclei
A Highlight of JLab E (HKS)
The First reliable observation of 7LHe
Old result on 7LHe
(M.Juric et al. NP B52 (1973) 1)
Inadequate for a serious comparison
A Test of Charge Symmetry Breaking
Begin with a theoretical description of these nuclei without CSB
A Naïve calculation of the CSB effect, which explains 4LH –4LHe and available s, p-shell hypernuclear data, predicts opposite shifts for A=7 ,T=1 iso-triplet L Hypernuclei.

24. An example of what we learn from Hypernuclei
A Highlight of JLab E (HKS)
-BL (MeV)
-6.730.02 0.2 MeV
from a L n n
The First reliable observation of 7LHe
A Test of Charge Symmetry Breaking
Compare with new measurements of 7LHe
Measured shift has the opposite sign to the predicted shift!
Begin with a theoretical description of these nuclei without CSB
A Naïve calculation of the CSB effect, which explains 4LH –4LHe and available s, p-shell hypernuclear data, predicts opposite shifts for A=7 ,T=1 iso-triplet L Hypernuclei.

25. An example of what we learn from Hypernuclei
A Highlight of JLab E (HKS)
-BL (MeV)
-6.730.02 0.2 MeV
from a L n n
The First reliable observation of 7LHe
A Test of Charge Symmetry Breaking Naïve theory does not explain the experimental result.
Begin with a theoretical description of these nuclei without CSB
A Naïve calculation of the CSB effect, which explains 4LH –4LHe and available s, p-shell hypernuclear data, predicts opposite shifts for A=7 ,T=1 iso-triplet L Hypernuclei.

26. Present Status of L Hypernuclear Spectroscopy
(2011)
To Fully Understand the L-N/N-N Force Differences  JLab and JPARC Programs
Tremendous Progress, but More Nuclei and Higher Precision are Needed
52LV
Updated from: O. Hashimoto and H. Tamura, Prog. Part. Nucl. Phys. 57 (2006) 564.

27. Complementary Additional Measurements Proposed for the 12 GeV Upgrade
The addition of measurements of p decay of hypernuclei will permit
Precise (~±20 keV) determination of  binding energies of a variety of ground state light hypernuclei
Determination and confirmation of ground state spin/parity
Direct measurement of  binding energy differences from multiple mirror pairs of light hypernuclei at ground state to investigate CSB and Coulomb effect
Searching for the neutron drip line limit of light hypernuclei – heavy hyper-hydrogen
Searching for evidence of the existence of isomeric hypernuclear states
Studying impurity nuclear physics – B(E2) measurement and medium effect of baryons – B(M1) measurement through lifetime

28. ✓Few-body aspects and YN, YY interaction
✓Mean field aspects of nuclear matter
✓Many body and astrophysical aspect

29. PR12-10-001 - Study of Light - Hypernuclei by Spectroscopy of Two Body Weak Decay Pions
Fragmentation of Hypernuclei
And Mesonic Decay inside Nucleus
Free:  p +  -
2-B: AZ  A(Z + 1) +  -
High momentum transfer in the primary production sends most of the background particles forward, thus pion momentum spectrum is expected to be clean with minor 3-boby decay pions:
High yield of hypernuclei (bound or unbound in continuum) makes high yield of hyper fragments, i.e. light hypernuclei which
stop primarily in thin target foil
High yield and unique decay feature allow high precision measurement of 2 body decay pion spectroscopy from which variety of physics may be extracted
- Decay at rest the pion momentum is uniquely connected to the well known structure of the decay nucleus, allow determination of B and spin-parity of the ground state of hyperfragments, study CSB