1. Dept. of Physics, Tohoku University H. Tamura
“Summary” -- Personal comments and personal 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 strangeness 2. 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
hypernuclei 5. 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
Impurity effect
in nuclear structure
　　 Changes of size,
deformation, clustering,
Appearing new symmetry, …
Properties and
behavior of baryons
in nuclei mL
New means to clearly probe the exotic nuclear structure
(e.g. triaxial deformation)
mL in a nucleus,
Single particle levels
of heavy L hypernuclei
...
Study of high-density
(strange) nuclear matter from s.p.e. of heavy L hypernuclei
Clues to understand
hadrons and nuclei
from quarks
Cold and dense
nuclear matter
with strangeness

5. 2. Elementary Process
Markowitz, Bydzovsky, Carman

6. CLAS data are wonderful, but very forward angles are not covered.
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. with much less distortion?
(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 4H 4He 0 MeV 3H+Λ 0 MeV 3He+Λ
-1.00
-1.24 1+ 1+
ΔB (He-H) = 0.24
-2.040.04 0+
-2.390.03 0+
ΔB (He-H) = 0.350.06 n p Λ n p Λ
Among these calculation, Nogga and his collaborators investigated the charge symmetry breaking effect by sophisticated 4-body calculation using modern realistic YN and NN interactions. These are results using Nijmegen soft core ’97e model. The calculated energy difference in the ground state is 0.07 MeV. And this value in the excited state is MeV. Both of energy difference in the ground state and the excited state are inconsistent with the data. At the present, there exist no YN interaction to reproduce the charge symmetry breaking effect. 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 17

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

19. Nakamura

20. Results on 16O target – 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. 4He(e,e’K+) The A = 4 isospin doublet 4He + p- 4H 4He spectorscopy
0 MeV
3H+Λ
0 MeV
3He+Λ
-1.00
-1.24 1+ 1+
ΔB (He-H) = 0.24
Suspicious.
Measure
at J-PARC
Tamura
g-ray
-2.040.04 0+
-2.390.03
4He + p-
Pion decay
spectorscopy 0+
ΔB (He-H) = 0.350.06 n p Λ n p Λ
Among these calculation, Nogga and his collaborators investigated the charge symmetry breaking effect by sophisticated 4-body calculation using modern realistic YN and NN interactions. These are results using Nijmegen soft core ’97e model. The calculated energy difference in the ground state is 0.07 MeV. And this value in the excited state is MeV. Both of energy difference in the ground state and the excited state are inconsistent with the data. At the present, there exist no YN interaction to reproduce the charge symmetry breaking effect. 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 21

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

23. Hyperhydrogen peak search
Achenbach
Hyperhydrogen peak search
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. Proposed to measure a(Ln) by K-stop d -> n L g -> at J-PARC
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
spherical
superdeformed
eL - b : linear relation
L single particle energy GS ND SD
41Ca L
40Ca(Pos)⊗L(s)
40Ca(Pos)⊗L(s)
40Ca(Pos) GS ND SD
40Ca
Energy surface eL
To analyze how the binding energy of a Lambda hyperon changes depending on deformation, we calculate the Lambda single particle energy as a function of beta.
Here Lambda single particle energy epsilon_Lmd is defined as the energy difference between the energy curves.
And the resulting curve of Lmd single particle energy is shown in the right figure.
It shows that Lambda single particle energy becomes shallower as beta increases, and the energy change is within 2 MeV.
41Ca L
39Ar
superdeformed
spherical

30. Hiyama 10Be BΛ = 8.94 MeV MeV 5/2 1/2+ 3/2- -1.58 (Jlab E01-11) 9Be
α＋α＋ｎ
α＋α＋ｎ＋Λ
1/2+
+0.1 ND SD
3/2-
Level reversion is occurred
by addition of a Λ particle.
10B(e,e’K+)10Be
(Jlab E01-11)
-1.58
9Be ND Λ
CAL
Small spin-splitting is
neglected to show.
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 = MeV)
2-, 3-
-8.14
MeV
1-, 2-
10Be Λ 30

31. Large overlap leads to deep binding
Triaxial deformation
Isaka
Triaxial deformation
Prolate deformation
If 24Mg is triaxially deformed nuclei
p-states split into 3 different state
Large overlap leads to deep binding
Middle
Small overlap leads to shallow binding
G.S.
Excitation Energy
25LMg
24Mg⊗L(s-orbit)
24Mg⊗L(p-orbit)
Split into 3 states?
Therefore, we can naively expect that the p-states of Mg25L will spit into three different states.
By observing them, triaxial deformation of the Mg24 ground state will be confirmed by experiments directly.
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. Results: Excitation spectra
Isaka
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
Lowest threshold : in between 8.3 and 12.5 MeV
Ne + 21 L

33. “New means to measure nuclear structure”
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. Now, we can make this plot with ~100 keV accuracy of absolute energy.
Millener
Now, we can make this plot
with ~100 keV accuracy of absolute energy.

37. Galibaldi
How??
How??

38. Serious problem in the nuclear physics at present
“The heavy neutron star puzzle”
Hyperons must appear at r = 2~3 r0
EOS’s with hyperons (or kaons) too soft -> can support M < 1.5 Msun
PSR J (2010) 1.97±0.04 Msun
PSR J (2013) 2.01±0.04 Msun
Serious problem in the nuclear physics at present M
NS radius　(km)
NS mass
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.
Hyperons
Quark matter
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 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. EOS and NS mass Rijken/Yamamoto + 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) BL data 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 Benhar Drago Schulze Motoba
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

51. (2) High resolution from a high-quality / intense beam
(and a thin target)
-> Highest resolution in reaction spectroscopy
~ 500 keV (FWHM)
-> High accuracy in decay pion (< 100 keV)
separate core levels (different hole states),
SCB in light systems
Complementary to g-spectroscopy:
DEex =2—10 keV
Only bound states
Only excitation energy (not absolute mass) -- Absolute value of the g.s. mass is necessary for physics of CSB, impurity, and s.p.e.

52. Hadron Hall Extension Plan
K1.8BR
K1.1BR/K1.1
COMET
K1.8
S=-2 systems KL
S=-1 systems
High-p
K1.1
2nd production target
Precise
S=-1
systems HR
3rd production
target
K10
Charm
S=-3
systems KL

53. Hadron Hall Extension Plan
K1.8BR
K1.1BR/K1.1
K-pp systems, K atoms, L(1405), h nucleus
COMET
LL and X hypernuclei
X atoms, YN scattering
H dibaryon
K1.8
S=-2 systems KL
S=-1 systems
High-p
g-spectroscopy and weak decays of L hypernuclei
S nuclear systems
YN scattering
f nucleus bound states
K1.1
Hadron mass in nuclei
Nucleon structure (Drell-Yan)
Charmed baryons
2nd production target
Precise
S=-1
systems HR
3rd production
target
K10
Precise S= -1 exp.
Single particle energies of L
n-rich L hypernuclei
Magnetic moments of L hypernuclei
Weak decays of L hypernuclei
X*, W* spectroscopy
LS, SS, LX, SX interactions
W hypernuclei
Multi K mesons in nuclei
Charmonium Spectroscopy
Charmonium and D mesons in nuclei
Charm
S=-3
systems KL

54. HIHR Line J-PARC ExHH Exp. Target A23 Dispersive Beam Achromatic Focus
Intensity: ~ 9x108 pion/pulse
(1.2 GeV/c, 56 m, 1msr*%,
270kW, 6s spill, Ni 54mm)
Dp/p ~ 1/10000
Exp. Target
A23
Achromatic
Focus
Dispersive Beam
High Res.
Spectrometer
Mass Slit
Prod. T
Electrostatic
Separator

55. Precise L single particle energies from (p+,K+)
Experimental data
E(sL, pL, dL , fL,..) < 0.1 MeV accuracy
E(sL) - E(pL), E(p1/2L1) - E(p3/2L) < 0.01 MeV accuracy
Precise L single particle energies from (p+,K+)
Problem:
Absolute energy calibration impossible
Huge cost of the new hall and HIHR line
Simulation
DE ~ 200 keV (FWHM)
High resolution (p+,K+), (e,e’K+)

56. Comparison Tamura Pochodzalla
JLab: High resolution/high accuracy S=-1 spectroscopy Pi decay spectroscopy Mainz: Elementary process, … J-PARC: S= -2 systems S=-1 g-spectroscopy K- and other mesons in nuclei FAIR: HI induced (n-righ/p-rich) hypernuclei S=-2 g-spectroscopy Anti-hyperon in nuclei
Tamura
Pochodzalla

57. Summary of summary

58. Motivations of strangeness nuclear physics
What can JLab answer?
My personal idea
Motivations of strangeness nuclear physics
Elementary H(e,e’K+)L
BB interactions
Unified understanding of BB forces by u,d ->u, d, s
Charge Symmetry Breaking
4LH pi decay, 4LH* production,..
particularly short-range forces by quark pictures
Test lattice QCD calculations
Impurity effect
in nuclear structure
　　 Changes of size,
deformation, clustering,
Appearing new symmetry, …
Properties and
behavior of baryons
in nuclei mL
New means to clearly probe the exotic nuclear structure
(e.g. triaxial deformation)
mL in a nucleus,
Single particle levels
of heavy L hypernuclei
...
Study of high-density
(strange) nuclear matter from s.p.e. of heavy L hypernuclei
e.g. 208LPb, A=50~100,
27LMg
Clues to understand
hadrons and nuclei
from quarks
Cold and dense
nuclear matter
with strangeness
27LMg
Needs more theoretical studies

59. Backup

60. First determination of Gp for 8 Hypernuclei (cont’d)
Bressani
New results from FINUDA
First determination of Gp for 8 Hypernuclei (cont’d)
M. Agnello et al., PLB 681 (2009) 139.
K. Itonaga, T. Motoba, Progr. Theor. Phys. Suppl. 185 (2010) 252.
H. Bhang et al., JKPS 59 (2011) 1461.
J.J. Szymansky et al., PRC 43 (1991) 849.
H. Noumi et al., PRC 534 (1995) 2936.
K. Itonaga, T. Motoba, Progr. Theor. Phys. Suppl. 185 (2010) 252.
H. Bhang et al., JKPS 59 (2011) 1461.
J.J. Szymansky et al., PRC 43 (1991) 849.
H. Noumi et al., PRC 534 (1995) 2936.
T. Motoba et al., NPA 534 (1991) 597.
A. Gal, NPA 828 (2009) 72.
T. Motoba, K. Itonaga, Progr. Theor. Phys. Suppl. 117 (1994) 477.
M. Agnello et al., PLB 681 (2009) 139.
K. Itonaga, T. Motoba, Progr. Theor. Phys. Suppl. 185 (2010) 252.
H. Bhang et al., JKPS 59 (2011) 1461.
J.J. Szymansky et al., PRC 43 (1991) 849.
H. Noumi et al., PRC 534 (1995) 2936.

61. Status of Strangeness NP @J-PARC
Status of J-PARC
Under preparation
Ready to run
Partly took data
Status of Strangeness
Tamura
S-n, X-n attractive
◆ n-rich hypernuclei by (p-,K+) ◆ g spectroscopy of L hypernuclei > LN, LN-SN (LNN) int. ◆ K-pp by 3He(K-,n) ◆ K-pp by d(p+,K+) 　 > KbarN int. in matter => K condensation in n star? ◆ S±p scattering 　 -> S-n (= S+p) (Quark Pauli effect) , S-p->LN int. L
E10
SHM
E13
fraction
=> Fraction of L in n-rich matter
E15
E27 K- p ρ
Property of high density nuclear systems
E40
=> S- exists in n-star?
◆ LL hypernuclei > LL interaction , LL correlation?
◆ X hypernuclear spectroscopy ◆ X atomic X rays
-> XN interaction
◆ H dibaryon search from H-> LL, Lpp-
-> Short-range BB force (Color magnetic int.)
E07
=> L fraction in Strange
Hadronic Matter
E05
E03, E07
=> X- exists in n-star?
E42

62. Nakamura

63. Rijken