“Summary” -- Personal comments and personal answers to the PAC requirements--

1. “Summary”-- Personal comments andpersonal answers to the PAC requirements-- Dept. of Physics, Tohoku University H. Tamura

2. 1. What is necessary to understand of the elementary • process of electro-production of strangeness2. Experimental study of light hypernuclei and YN • interaction including Charge Symmetry Breaking (CSB) • effect and LN-SN coupling.3. What can be learned from precise determination of L • binding energies • 4. Deformation of core-nucleus and energy levels of L • hypernuclei5. Detailed spectroscopy of heavy hypernuclei and • potential impacts of measurement to mean-field theory, • shell-models and single particle nature of L in deep • inside of nuclei.6. Uniqueness of JLab hypernuclear program in contrast to • other facilities such as J-PARC, Mainz, future FAIR

3. Contents 1. Elementary Process 2. LN interaction from light hypernuclei --- Charge Symmetry Breaking 3. Impurity effects 4. Single Particle Energies of L hypernuclei 5. Uniqueness of JLab

4. Motivations of strangeness nuclear physics What can JLab answer? BB interactions Unified understanding of BB forces by u,d ->u, d, s Charge Symmetry Breaking particularly short-range forces by quark pictures Test lattice QCD calculations mL Impurity effect in nuclear structure Changes of size, deformation, clustering, Appearing new symmetry, … Properties and behavior of baryons in nuclei New means to clearly probe the exotic nuclear structure (e.g. triaxial deformation) Study of high-density (strange) nuclear matter from s.p.e. of heavy Lhypernuclei mLin a nucleus, Single particle levels of heavy L hypernuclei ... Cold and dense nuclear matter with strangeness Clues to understand hadrons and nuclei from quarks

5. 2. Elementary Process Markowitz, Bydzovsky, Carman

6. Carman CLAS: Wonderful data for cross sections and all combinations of beam, target, and recoil polarization states. - Precision data – broad kinematic coverage - Program includes “complete” experiments on both proton and neutron targets CLAS data dominates the world’s strangeness physics database for both photoand electroproduction cross sections and spin observables.lso essential data for photoproduction models CLAS data are wonderful, but very forward angles are not covered.

7. Markowitz

8. Markowitz

9. The largest merit of (e,eK+) is the accuracy of absolute energy (<100 keV), but with demerits of non-selectivity of states and difficulty in state assignment. The cross section is the almost only observable that can be used for state assignment. For this purpose, reliable theoretical calc’s of the cross sections are essential, and therefore the elementary cross section must be precisely known. Target thickness should be carefully monitored: -> The waterfall target looks good.

10. (p+,K+) cross sections well reproduced by DWIA calc. Hashimoto and Tamura, PPNP (2005) Calc. by Motoba and Itonaga Why not in (e,e’K+) with much less distortion?

11. Bydzovsky Also essential data for photoproduction models

12. 3. LN interaction from light hypernuclei --Charge Symmetry Breaking

13. LN interaction has been rather well known through interplay between Theories of BB models (Haidenbauer, Rijken) and Theories of hypernuclear structure (Millener, Hiyama, Motoba, Wirth) with Good experimental data from Hall A (Urciuoli), Hall C (Nakamura) KEK/BNL/J-PARC (Tamura), FINUDA (Bressani) except for CSB problem -> A big surprise? (Hiyama, Gibson)

14. Millener Spin-dependent force strengths well determined from p-shell Level structures -> feedback to BB int. models

15. Wirth Ab-initio calculation of p-shell hypernuclei w/S mixing is now on-going! –Stringent test of YN interactions

16. Charge symmetry breaking Exp: Achenbach, Urciuoli, Nakamura, Tamura, Tang, Theor: Millener, Hiyama, Haidenbauer, Nogga, Gibson, Motoba

17. Achenbach The A = 4 isospin doublet 0 MeV 3H+Λ 3He+Λ 0 MeV -1.00 1+ -1.24 1+ ΔB (He-H) = 0.24 -2.040.04 0+ -2.390.03 n n 0+ ΔB (He-H) = 0.350.06 n p Λ p Λ p 4H Λ 4He Λ • Nucleon-hyperon interaction can be studied by strange mirror pairs • Coulomb corrections are < 50 keV for the 4ΛH - 4ΛHe pair • Energy differences of 4ΛH - 4ΛHe pair much > than for 3H - 3He pair

18. Nakamura Systematic error of absolute energy ~100 keV!

19. Nakamura

20. Results on 16Otarget – Hypernuclear Spectrum of 16NL Fit 4 regions with 4 Voigt functions c2/ndf = 1.19 Binding Energy BL=13.76±0.16 MeV Measured for the first time with this level of accuracy (ambiguous interpretation from emulsion data; interaction involving L production on n more difficult to normalize) Urciuoli Within errors, the binding energy and the excited levels of the mirror hypernuclei 16O and 16N (this experiment) are in agreement, giving no strong evidence of charge-dependent effects 0.0/13.760.16 There seems to be little CSB effects for A>4. Reliable data for A=4 should be measured.

21. The A = 4 isospin doublet 4He(e,e’K+) spectorscopy 0 MeV 3H+Λ 3He+Λ 0 MeV -1.00 1+ -1.24 1+ ΔB (He-H) = 0.24 g-ray -2.040.04 0+ -2.390.03 n n 0+ ΔB (He-H) = 0.350.06 n p Λ p Suspicious. Measure at J-PARC Tamura Λ p 4H 4He + p- Λ 4He Λ Pion decay spectorscopy • Nucleon-hyperon interaction can be studied by strange mirror pairs • Coulomb corrections are < 50 keV for the 4ΛH - 4ΛHe pair • Energy differences of 4ΛH - 4ΛHe pair much > than for 3H - 3He pair

22. Pion decay spectroscopy A powerful tool particularly for CSB Achenbach, Tang, Motoba Tang Proposing Setup at JLab 12

23. Achenbach Hyperhydrogen peaksearch Emulsion data preliminary MAMI data local excess observed inside the hyperhydrogen search region Sys. Error: ± 110 (calib.) ± 40 (stab.) keV/c

24. World data on A = 4 system Achenbach

25. Gibson Proposed to measure a(Ln) by K-stop d -> n L g -> at J-PARC

26. Motoba 4He(e,e’K+) spectorscopy

27. What is the origin of CSB ? Construct YN interaction from chiral EFT -> applied to CSB problem Haidenbauer, Nogga S Admixture from S-L coupling determines CSB effect

28. 4. Impurity effects Hiyama, Isaka, Nakamura

29. BL is a measure of deformation Isaka eL - b: linear relation 40Ca L single particle energy 40Ca(Pos) 41Ca SD L Energy surface ND GS SD ND spherical 40Ca(Pos)⊗L(s) GS 41Ca superdeformed L 40Ca(Pos)⊗L(s) eL 39Ar superdeformed spherical

30. MeV 5/2 Hiyama +0.6 MeV α＋α＋ｎ α＋α＋ｎ＋Λ 1/2+ +0.1 ND SD 10Be Level reversion is occurred by addition of a Λ particle. 10B(e,e’K+)10Be (Jlab E01-11) 3/2- Λ -1.58 9Be ND Λ Small spin-splitting is neglected to show. CAL EXP BΛ = 8.94 MeV If we observe positive states and negative states, we find that Λ-separation energies are dependent on the degree of deformation. Please observe the positive parity states at Jlab. -7.35 0+ , 1+ (BΛ = 9.11 0.22 MeV) 2-, 3- -8.14 -10.52 MeV 1-, 2- 10Be Λ

31. Isaka Triaxial deformation p-states split into 3 different state If 24Mg is triaxially deformed nuclei Triaxial deformation Prolate deformation Largeoverlap leads to deep binding 25LMg Middle Split into 3 states? Excitation Energy 24Mg⊗L(p-orbit) G.S. Small overlapleads to shallow binding 24Mg⊗L(s-orbit) Observing the 3 different p-states is strong evidence of triaxial deformation Our (first) task: To predict the level structure of the p-states in 25LMg

32. Isaka Results: Excitation spectra • 3 bands are obtained by L hyperon in p-orbit • 24Mg⊗Lp(lowest), 24Mg⊗Lp(2nd lowest), 24Mg⊗Lp(3rd lowest) Splitting of the p states 21 L Ne + L Lowest threshold : in between 8.3 and 12.5 MeV

33. L Impurity - changes the size/deformation of the core nucleus ? => Only for light-clusterized nuclei (7LLi 19% shrinkage from 6Li: Tanida et al.) - is a clear probe of nuclear shape/nuclear density. “New means to measure nuclear structure” • Distinguish Normal Deformed / Super Deformed states • 10LBe <= 10B(e,e’K+) : level inversion • Probably (spin)-parity cannot be assigned. • Hopefully distinguished from cross sections. But how small ? • Evidence for triaxial deformation (there are implications but no clear evidence.) • 27LMg <= 27Al (e,e’K+) • Three band heads should have large cross sections.

34. 5. Single Particle Energies of L hypernuclei ( and neutron star matter)

35. Nakamura

36. Millener Now, we can make this plot with ~100 keV accuracy of absolute energy.

37. Galibaldi How?? How??

38. “The heavy neutron star puzzle” M • Hyperons must appear at r = 2~3 r0 • EOS’s with hyperons (or kaons) too soft -> can support M < 1.5Msun PSR J1614-2230 (2010) 1.97±0.04 Msun PSR J0348-0432 (2013) 2.01±0.04 Msun Serious problem in the nuclear physics at present • Unknown repulsion at high r • Strong repulsion in three-body force including hyperons are necessary. (NNN, YNN, YYN, YYY) • Phase transition to quark matter ? • (quark star or hybrid star) • But we have no data on BBB force • at high r nuclear matter, • except for indirect info. in HI collisions. NS mass Hyperons Quark matter NS radius(km) Quark Meson Coupling model with hyperons J.Stone et al., Nucl. Phys. A792(2007)341

39. Vidana

40. Vidana

41. Vidana TBF repulsion from meson exchange models is not enough

42. L’s single particle energy in hypernuclei will solve this serious problem? Rijken Nijmegen ESC08 reproduces (almost) all the hypernuclear data as well as all the NN/YN scattering data. • Y. Yamamoto/Rijken • BHF calc. from ESC08 • => reproduces all the L s.p.e. data (~1 MeV accuracy)very well • with no adjustable parameters => but EOS is too soft. • ESC08 + “3body/4body repulsion in YNN,YYN,YYY..” with the same size as the NNN repulsion which reproduces HI collision data (“universal 3B repulsion”). => can support 2Msun NS. • => slight change of BL by +- 0.5 MeV between A~30 and 208. Even with r=r0 nuclei, we can see the effect of a (short-range) 3-body YNN/YYN/YYY repulsion in BL , if the repulsion is large enough to support 2Msun NS.

43. + 3B/4B repulsion in NNN +YNN Y. Yamamoto

44. Rijken/Yamamoto EOS and NS mass + 3B/4B repulsion in NNN +YNN + 3B/4B repulsion in NNN only + 3B/4B repulsion in NNN +YNN ESC08 only ESC08 only + 3B/4B repulsion in NNN

45. We need accurate (< 0.1 MeV) BLdata for at least three hypernuclei, a heavy (A~200), a medium-heavy (A~100-50), and medium (A~30) 208L Pb is quite important, as far as experimentally feasible. Theoretical efforts are also important: Include relativistic effects Physical picture of 3B/4B forces -- 3B force from lattice?? L hyperon in the only probe that can sense static high-density (but, up to ~r0) nuclear matter. ( HI collisions are not static and difficult to treat.)

46. Is there a correlation between the slope in BL(A) plot and the NS maximum mass Independently of theoretical treatment ?? NS maximum mass Slope: [BL(A’)-BL(A)]/(A’-A)

47. Motoba From such calculation, we can separate excited hole states and extract the g.s. energy reliably.

48. Pederiva, Lonardoni Quantum Monte Carlo for hypermatter with 3B force Benhar Spectral function of L in 208Pb Drago Neutron star with D, hyperons, and quark-hybrid star Schulze Neutron star with hyperons from BHF + SHF Motoba Pionic weak decays of hypernuclei

49. 6. Uniqueness of JLab

50. Uniqueness of JLab (1) Absolute mass in ~100 keV accuracy with HKS (a wide acceptance both for L and S0) Nakamura (HRS needed a slight correction in BL ) Urciolli c.f. (p+,K+) and (K-,p-) reactions (n->L) have no means for absolute calibration. Affected by emulsion data. (p+,K+) error in BL: typ. ~0.5 MeV(thick target)+ emulsion error 0.5 MeV should be shifted in all the (p+,K+) BL values. Millener Confirmed from the accurate (e,e’K+) data -> Definite data for CSB from light hypernuclei -> L’s s.p.e. in medium/heavy hypernuclei