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

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

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

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

 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

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

 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 !

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

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

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 × JLab E (Hall-C) setup

JLab E JLab E KaoS 2008 P.Achenbach et al.

L.Tang et al., PRC 90, , (2014). T.Gogami et al., to be submitted soon S.N.Nakamura et al., PRL 110, , (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.

 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 = = 71 keV

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)

Hiyama et al. PRC PTP 128 (2012)  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

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

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

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

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)

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

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

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

+

Small CSB

 n pp  n np   0.27 MeV 0.16 MeV Mainz New data : PRL 114, (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

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 , 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

JLab E T.Motoba, JLab Hypernuclear WS (2014) peakB  (MeV) s p-8.47 d-1.08 s p d

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

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.

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

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

 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 ( 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.