1. Satoshi N. Nakamura, Tohoku University Study of Lambda hypernuclei with electron beams JLab HKS-HES collaboration, 2009, JLab Hall-C On behalf of JLab HKS-HES and Hypernuclear Collaborations Recent and near-future publications from HKS-HES collaboration

2. Baryon (Hyper) Nucleus Neutron Star Baryon Interaction Spectroscopy of Hypernuclei NN scat. LQCD

3. Nuclear Force Lots of NN scattering data Nuclear Structure Normal/Exotic nuclei Established Calculation Tech. Cluster Model Shell Model Mean Field Hyperon Force Limited YN/YY scattering data Nuclear Structure Hypernuclei Baryon Interaction QCD Quark degree of freedom SU f (3) Symmetry Lattice QCD Modarn baryon Interaction models

4. s-quark exchange s,sbar pair creation (K -,  - ) (  +,K + ), (e,e’K + )

5.  Electromagnetic production  Convert Proton to Lambda : Isomultiplet partner to well studied HY by ( ,K), (K,  ) Absolute energy calibration with p(e,e’K + )    High quality primary beam High energy resolution (< 1MeV) Thin enriched target

6. MethodResolutionAbsolute EYieldcomments (e,e’K + )0.5 MeV ◎△ 100nb/sr (  +,K + )1.5 – 2 MeV○ (norm 12  C)○ 10  b/sr (K -,  - )~2 MeV○ (norm 12  C) ◎ 1 mb/sr  -ray0.003 MeV× (SA △ ) - Decay  0.1 MeV ◎ (only g.s.) (SA ×)Fragments

7.  Huge e’ Background due to Bremsstrahlung and M  ller scattering Signal/Noise, Detector  Less Hypernuclear Cross Section  Coincidence Measurement (e’, K + ) Limited Statistics DC beam is necessary High Quality Electron Beam is Essential !

8. E05-115 (2009) : HKS+HES, new Chicane beamline, Splitter ,  0, 7  He, 12  B, 52  V Light to medium-heavy Hypernuclei E89-009 (2000) : Existing spectrometers, SOS + Enge Proof of Principle E 01-011 (2005) : Construction of HKS, Tilt Method ,  0, 7  He, 12  B, 28  Al Light Hypernuclei E94-107 (2004-5) Two HRSs + SC Septum ,  0, 9  Li, 12  B, 16  N Light Hypernuclei

9. JLab Hall-C HNSS (2000) HKS (2005) HKS+HES (2009) JLab Hall-A HRS+HRS (2004) Mainz MAMI-C A1 KaoS (2008-) HKS HES

10. Pre-chicane beam line θ e’ = 6.5 ± 5.0 deg. θ K = 5.7 ± 4.6 deg. 7.0 msr 8.5 msr Δ p/p ~ 2 × 10 -4 JLab E05-115 (Hall-C) setup

11. JLab E01-011 JLab E05-115 KaoS 2008 P.Achenbach et al.

12. L.Tang et al., PRC 90, 034320, (2014). T.Gogami et al., to be submitted soon S.N.Nakamura et al., PRL 110, 012502, (2013). C.Chen et al., preparing draft Triggered active CSB discussion Information about  ’s single particle potential Y.Fujii et al. NIM A795 (2015) 351. T.Gogami et al. NIM A729 (2013) 816.

13.  n pp  n np   0.35 MeV 0.24 MeV Coulomb effect is small. Charge Symmetry Breaking Charge Symmetry Breaking Effect of the  N interaction 4H4H 4  He cf) B( 3 H)-B( 3 He)-  B c = 764-693 = 71 keV

14. N  N   mass difference ~ 80 MeV < N  mass difference ~ 300MeV M(            8MeV A.R.Bodmer&Q.N.Usmani, PRC 31(1985)1400. Phenomenological potential : Consistent understanding of 0 +, 1 + of 4  H, 4  He Modern ChPT-NLO calculation predicts 3NF effect is < 100keV but NLO calculation cannot explain experimental results for A=4, T=1/2, hypernuclei. (Nogga, HYP2012)

15. Hiyama et al. PRC 80.054321 PTP 128 (2012) 105..  n np  p np  p n  7  Li*  p  7  Be p  n n  7  He 4H4H 4  He 10  B  n   10  Be  p   Experimental B   CSB No reported B  67 events 98 events 167 events 15 events 3 event 10 events Exp. Data : Emulsion

16. 6 He : 2n halo  behaves like glue E.Hiyama et al. PRC 80, 054321 (2009)

17. E01-011 (2005) E01-011 (2005) E05-115 (2009) E05-115 (2009) SNN et al., PRL 110, 012502 (2013) T.Gogami, Doctor Thesis (2014) Tohoku Univ. Assumed CSB potential may be too naïve. New measurements on A=4 systems are necessary.

18. T.Gogami, Doctor Thesis (2014) Tohoku Univ. CSB interaction test in A=7 iso- triplet comparison E01-011 (2005) E01-011 (2005) E05-115 (2009) E05-115 (2009) E Λ (3/2 +,5/2 + ) [MeV] E.Hiyama et al., PRC 80, 054321 (2009) 1.70 M.Sotona et al., PTP 117 (1994) 1.79 D.J.Millener Private Comm. (2013) 1.72

19. 0.54 MeV (FWHM) 1.45 MeV (FWHM) 12 C( π +,K + ) 12 Λ C KEK-PS E369 Absolute MM calibration 12  C gs energy from emulsion 0.71 MeV (FWHM) L.Tang, C.Chen, T.Gogami et al. Phys. Rev. C 90 (2014) 034320.

20. Reference for all ( , K) B  data: B  ( 12  Cg.s.) = 10.76 +-0.19MeV Statistical error only 11 C (3/2-) : Ex = 4.8MeV

21. B  ( 12  Bg.s.) = 11.45 +-0.07 MeV (# of events) Emulsion Result (M.Juric et al.) B  ( 12  Bg.s.) = 11.38 +- 0.02 (stat) MeV (JLab E05-115) Totally independent measurement

22. B  (emulsion)-B  ( ,K) [MeV] The difference of the same values measured by different methods.

23. +

24. Small CSB

25.  n pp  n np   0.27 MeV 0.16 MeV Mainz New data : PRL 114, 232501 (2015) J-PARC E13 (  -ray; hyperball) has successfully measured! Only accessible by the 4 He(e,e’K + ) 4  H at JLab  -ray : level spacing Decay  : ground state

26. Cutoff of potential in coupled channel LS equation based on Ch EFT vs. B   4  H). J. Haidenbauer, JLab Hypernuclear WS, May 2014 Measureable with the (e,e’K) reaction at JLab Recently re-measured at Mainz (PRL 114.232501, 2015) Existing experimental uncertainty may be larger. Since CSB term is not consistently understood for A=4 and A=7 hypernuclei. CSB potential is too naïve or A=4 data have problem. 4  H data indicate : LO Ch EFT depends much on cut-off parameter (especially 1 + ). NLO looks underbind 4  H Long range 3BFs need to be estimated with reliable experimental inputs N 2 LO

27. JLab E01-011 T.Motoba, JLab Hypernuclear WS (2014) peakB  (MeV) s-16.54 p-8.47 d-1.08 s p d

28. K(HKS) x HRS (e’) Only JLab : Beam + Spectrometers for (e,e’K + )

29. Higher Pe’ with HRS Excellent momentum resolution (2x10 -4 ) Orbit is long but no problem for e’ HKS Excellent momentum resolution (2x10 -4 ) with short orbit to avoid decay loss of kaons with lower momentum (1.2 GeV/c). Large solid angle as well as momentum acceptance. High resolution Large Yield (best virtual photon energy & HKS acceptance) Established in Hall-C Allow to use higher (4.5 GeV) incoming electron beam. Background from Bremsstrahlung will be boosted to forward. Introduction of Septum magnet Easier and more reliable calibration of HKS-HRS systems separately. Good Signal to Noise ratio Established in Hall-A Electron BG will be 1/40 of Hall-C exps. Keep resolution and 5.4 times larger yield than Hall-A exp. Advantage of the proposed setup over previous experiments.

30. YN interaction Hyperon puzzle in neutron stars Charge Sym. Breaking Light Hyp.Nucl. Mid-Heavy Hyp.Nucl. p(e,e’K + ) ,  0 Exotic systems ([n  ],[nn  ]) Established lightest HY ( 3  H) 4  H spectroscopy Isospin dependence ( 40  K, 48  K) A dependence of B  ( 40  K, 89  Sc, 208  Tl) Part I.Part II. Conditionally Approved (C2) by PAC43

31. Updated from: O. Hashimoto and H. Tamura, Prog. Part. Nucl. Phys. 57 (2006) 564. (2011) 52  V 6H6H (2014)

32.  We have been developing large magnetic spectrometers (HKS, HES) and techniques in the last decade at JLab and (e,e’K + ) HY spectroscopy is now established.  Best spectroscopy of 12  B was performed and absolute binding energy calibration implies a shift (500-600 keV) of 12  C emulsion B  which is the reference to all (  ,K  ) spectrosopy binding energies.  Binding energy of 7  He gs was determined. Important input for  N CSB potential. Excited state of 7  He was clearly observed.  New spectroscopy on 10  Be and 28  Al Hypernuclear spectroscopy with electron beam is unique and quite effective way to investigate the baryon interaction. Currently only JLab can perform (e,e’K + ) spectroscopy. Combined with decay  at Mainz,  -ray spectroscopy at J-PARC, CSB and EoS of NS should be studied in timely manner.