1. Hypernuclear investigation Few-body aspects and YN, YY interaction –Short range characteritics ofBB interaction –Short range nature of the LN interaction, no pion exchange: meson picture or quark picture ? –Spin dependent interactions –Spin-orbit interaction, ……. –LS mixing or the three-body interaction Mean field aspects of nuclear matter –A baryon deep inside a nucleus distinguishable as a baryon ? –Single particle potential –Medium effect ? –Tensor interaction in normal nuclei and hypernuclei –Probe quark de-confinement with strangeness probe Astrophysical aspect –Role of strangeness in compact stars –Hyperon-matter, SU(3) quark-matter, … –YN, YY interaction information

2. Experimental evidence for single particle orbits deep in nucleus They cannot be seen by nucleons Only hyperons (  ) which are free from Pauli blocking make it possible. Hotchi et al., Phys.Rev.C 64 (2001) 044302 What do we find from  hypernuclear data?  feels a weaker potential than nucleons U  = -30 MeV (c.f. U N = -50 MeV) -> Attraction :  -N < N-N Mass of hypernucleus B  (MeV) Better energy resolution is necessary for more studies on  N interaction : L N spin-dependent forces, L N- S N force,.. SKS at KEK-PS Unified understanding of B-B interactions in the quark (+meson) picture together with  and  hypernuclear data

3. Comparison with BB interaction models  S  S N T (MeV) ND -0.048 -0.131 -0.264 0.018 NF 0.072 -0.175 -0.266 0.033 NSC89 1.052 -0.173 -0.292 0.036 NSC97f 0.754 -0.140 -0.257 0.054 ( “Quark” 0.0 -0.4 ) Exp. 0.4 -0.01 -0.4 0.03 Tensor forces (T) is well explained by meson-exchange models. Strength equivalent to quark-model LS force by Fujiwara et al. G-matrix calc. by Yamamoto Spin-orbit forces (S L, S N ) cannot be explained by meson models. Data seems to favor quark models. --but 9 L Be calculation by Fujiwara et al. (quark+meson) cannot reproduce it. Courtesy H. Tamura

4. World of matter made of u, d, s quarks ordinary nuclei L, S hypernuclei LL, X hypernuclei Neutron-rich nuclei Proton-rich nuclei higher density N u ~ N d ~ N s Strangeness in neutron stars ( r > 3 - 4 r 0 ) Strange hadronic matter (A → ∞) 3-dimensional nuclear chart LN interaction

5. HYPERNUCLEAR PHYSICS Hypernuclei are bound states of nucleons with a strange baryon (Lambda hyperon). Extension of physics on N-N interaction to system with S#0 Internal nuclear shell are not Pauli-blocked for hyperons Spectroscopy Unique aspects of strangeness many body problems   - N interaction A hypernucleus is a “laboratory” to study nucleon- hyperon interaction (  -N interaction).

6. High resolution, high yield, and systematic study is essential using electromagnetic probe and BNL 3 MeV Improving energy resolution KEK336 2 MeV ~ 1.5 MeV new aspects of hyernuclear structure production of mirror hypernuclei  charge simmetry breaking ??? energy resolution ~ 500 KeV 635 KeV

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

9. J LAB Hall A Experiment E94-107 16 O(e,e’K + ) 16  N 12 C(e,e’K + ) 12    Be(e,e’K + ) 9  Li H(e,e’K + )  0 E beam = 4.016, 3.777, 3.656 GeV P e = 1.80, 1.57, 1.44 GeV/c P k = 1.96 GeV/c q e = q K = 6° W  2.2 GeV Q 2 ~ 0.07 (GeV/c) 2 Beam current : <100 m A Target thickness : ~100 mg/cm 2 Counting Rates ~ 0.1 – 10 counts/peak/hour A.Acha, H.Breuer, C.C.Chang, E.Cisbani, F.Cusanno, C.J.DeJager, R. De Leo, R.Feuerbach, S.Frullani, F.Garibaldi*, D.Higinbotham, M.Iodice, L.Lagamba, J.LeRose, P.Markowitz, S.Marrone, R.Michaels, Y.Qiang, B.Reitz, G.M.Urciuoli, B.Wojtsekhowski, and the Hall A Collaboration and Theorists: Petr Bydzovsky, John Millener, Miloslav Sotona E 94107 C OLLABORATION E -98-108. Electroproduction of Kaons up to Q2=3(GeV/c)2 (P. Markowitz, M. Iodice, S. Frullani, G. Chang spokespersons) E-07-012. The angular dependence of 16 O(e,e’K + ) 16 N and H(e,e’K + ) L (F. Garibaldi, M.Iodice, J. LeRose, P. Markowitz spokespersons) (run : April-May 2012) Kaon collaboration archival paper coming

10. Hall C collaboration and experiments

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

12. Hall C hardware contribution

13. slide(s) 4 and 5 - Slide 4 : nuclei studied and physics learned - Slide 5 : effort in analysis and the physics we broadly anticipate for 12 GeV

14. Slide 4 Li-7, Li-9, B10, C12, N-16, Si 1. elementary process: The study of p(e,e′K+)L/S is important not only for the understanding of strangeness electroproduction but also for absolute missing mass calibration of the spectrometer systemsby using the well known masses As can be seen, 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. 2. Li-7 Preliminary analysis of the results of E01-011 [32] shows a clear peak of the 7He groundstate with enough statistics for the first time. The obtained binding energy was compared withresults from the cluster calculation. Surprisingly, inclusion of a CSB term in the N interactionmakes the discrepancy between experiment and theory worse, though the CSB term is essentialfor A=4 hypernuclei. This indicates that current understanding of the CSB effect in the Ninteraction potential is still imperfect and further systematic study is necessary. 3. Be-9: Data show some disagreement between the standard model of p-shell hypernculei and the measurements, both for the position of the peaks and for the cross sections.The theoretical result for the ground-state doublet agrees quite well with the experimental value but predictions for the excited state doublets are about two times smaller. The cross sections depend very much on the proton removal spectroscopic factors for 9Be. The disagreement could be due a number of deficiencies in the structure or reaction calculation. 4. B-10 ? 5. C-12 : a high-quality 16 N hypernuclear spectrum has been for the first time a measurable strength with good 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 distribution of strength within several MeV on either side of the strong p peak should stimulate theoretical work to better understand the p_L region. 6. O-16 For the first time with sub-MeV energy resolution, thus putting tighter restrictions on the spacings of the levels contributing to each peak. The measured cross sections are in good agreement with the values predicted using the SLA model and simple shell model N calibrated against the elementary (e, e′K+) reaction on hydrogen, has been obtained. The fourth peak ( in p state) position disagrees with theory. This might be an indication of a large spin-orbit term S 7. Si ? 8. ?

15. Prospectives Future mass spectroscopy

16. what we would like from Mont (????)