1. (S=-1) Hypernuclear Physics at J-PARC
(S=-1) Hypernuclear Physics at J-PARC
Deptartment of Physics, Tohoku University
Advanced Science Research Center, JAEA
H. Tamura

2. Contents 1. Present status of J-PARC
2. gamma-ray spectroscopy of hypernuclei
3. Hyperon-nucleon scattering
4. Future experiments and Hadron hall extension
S=-2 hypernuclei
K-N interactions
=> Tanida’s talk on Wednesday

3. 1. Present Status of J-PARC

4. Ten years since J-PARC Hadron Facility started operation in 2009

5. J-PARC Hadron Hall nuclear/hadron experiments (2019)
✔ Q+ pentaquark search (E19: Naruki)
✔ n-rich L hypernuclei (E10: Sakaguchi)
✔ K-pp via (p+,K+) (E27: Nagae)
✔ g spectroscopy of L hypernuclei (E13: Tamura)
✔ X hypernuclei (E05: Nagae)
✔ LL and X hypernuclei in emulsion + X-atom X rays
(E07: Nakazawa, Imai, Tamura)
　　Sp scattering (E40: Miwa)
　　X-atomic X rays (E03:T anida, Yamamoto)
H dibaryon search (E42: Ahn, Imai)
X hypernuclei via (K-,K+) (E70: Nagae)
Nucleon resonances (E45: Hicks, Sako)
Pion double charge exch. (E08: Kurtenkova)
Weak decays of A=4 L hyp. (E22: Sakaguchi, Ajimura)
w nucleus (E26: Ozawa)
J-PARC Hadron Hall nuclear/hadron experiments (2019)
✔ 9 experiments were finished in ten years.
Many experiments are still waiting…
Beam
Dump
K1.8
✔ K- pp via (K-,n) (E15: Iwasaki,Nagae)
✔ L(1405) (E31: Noumi)
✔ K-He X rays (E62: Hayano,Okada)
K-d X rays (E57: Zmeskal, Hashimoto) KL
K1.8BR
g spectroscopy of L hyp. (E63:Tamura）
LNN weak decay (E18:Bhang,Outa)
f nucleus (E29:Ohnishi)
Production
target (T1)
High-p Line
Vector meson mass　(E16:Yokkaichi）
Charmed baryons (E50:Noumi)
K1.1
30 GeV primary beam
✔ Finished
Fully approved
Stage-1 approved

6. Recent news on J-PARC Hadron Hall
HYP2018 at Portsmouth
E13 (g-ray): 4LHe and 19LF g-rays were observed.
E15 (K-pp): A clear signal for K-pp was observed at BK ~ 50 MeV
E05 (K-,K+): The spectrum suggests X hypernuclear bound states
T.O. Yamamoto et al., PRL 115 (2015) ; S.B.Yang et al., PRL120 (2018)
M. Iwasaki et al., PLB 789 (2019) 620; Y. Sada et al., PTEP 2016 (2016) 051D01; T. Hashimoto et al., PTEP 2015 (2015) 061D01.
T. Nagae et al., PoS INPC2016 (2017) 038.
After HYP2018
E07 (emulsion): On-going analysis has found more and more LL and
X hypernuclear events.
E31 (L(1405)) successfully measured the L(1405) spectrum shape with decomposed isospin.
E62 (K-He X-ray) with TES successfully measured the shift.
E40 (Sp scattering) is running successfully.
High-p beamline just constructed. E16 (f mass in medium) will start soon.
E03 (X-atom X-ray) and E42 (H search) will run in FY 2020.
One-year shutdown for MR power supply replacement is planned in FY2021,
when a new production target for 100 kW target will be installed.
H. Ekawa et al., PTEP 2019 (2019) no.2, 021D02

7. 2. g-ray spectroscopy of L hypernuclei

8. g-ray data of hypernuclei (2018) Hypernuclear g-ray data (2019)
19F(K-, p-g) J-PARC E13
1/2+ 0 3/ 5/ 1/ 1+ 3+ 0-
1.081
0.937
PRL 120 (2018)
4He(K-, p-g) J-PARC E13
4He 3H
PRL 115 (2015) L
1.406
18F
19F L
6.041 1- 2-
3/2- M1
p-shell: LN spin-dependent interaction strengths.
s-shell: L-S coupling and Charge Symmetry Breaking
sd-shell: Heavier hypernuclear structure and
LN interaction in a larger density?
NPA835 (2010) 422
PTEP (2015) 081D01

9. Energy levels of A=4 mirror hypernuclei
Bedjidian et al.
PLB 83 (1979) 252 etc.
T.O. Yamamoto et al.,
PRL 115 (2015)
A. Esser et al.,
PRL 114 (2015) 12501
4LH
4LHe p n L
A large Charge Symmetry Breaking effect is confirmed!

10. Mass-gated g-ray spectra
19LF results
Mass-gated g-ray spectra
S.B.Yang et al., PRL120 (2018)
19LF (sL) region
16O core n p L
sd orbit

11. LN spin-spin interaction strength for wide A hypernuclei
PRL 115 (2015)
Sensitive to wavefunction overlap
1.406 MeV
New!
sLsN
PRL 84 (2000) 5963
LN interaction and theoretical framework work well for heavier hypernuclei.
s, p, sd shells consistently understood.
=> Hope to extract LNN force effect from heavy hypernuclear data.
sLpN
New!
0.315 MeV
PRL120 (2018)
Millener 305 keV (phenom.)
Umeya keV (NSC97e+f)
Predictions
sLdN

12. Future plans of g spectroscopy
Further study of CSB
Re-measure 4LH(1+->0+)
p-shell hypernuclei via (p-,K0) reaction
B(M1) measurement for gL of a L in medium
Structure of medium to heavy hypernuclei
E1(pL->sL) for density dependent LN interaction
Origin of spin-orbit splitting
Impurity effects in deformed hypernuclei
E63 (approved)

13. Energy levels of A=4 mirror hypernuclei
T.O. Yamamoto et al.,
PRL 115 (2015)
M. Bedjidian et al.
Phys. Lett. B 83, 252 (1979).
NaI counters (bad resolution)
a large Doppler broadening
stopped K- on 7Li
4LH
4LHe p n L
4LH g-ray should be precisely measured (E63).

14. Production of 4LH* via in-flight (K-,p-) on 7Li target
Gating highly unbound region of the missing mass
-> a peak at ± MeV with systematic error
It should be 4LH g-ray
M. May, PRL 51(1983)2085
1.1
Possible reaction process
K- + a + t -> L + 3He + p- + t
L+3He -> 4LHe (0+ only non-spin-flip)
L+ t > 4LH (Both 0+/1+ ratio =1:3 expected)
Ex(7LLi*) >19.3 MeV
1.4
7Li
Higly unbound
7LLi*(pnpL substitutional state)
Byproduct
Ex(7LLi*) =12 MeV
K- + a + t ->
a + 3LH* + p-
T=1
Bound region
T=0
NaI: 74 keV (FWHM) at 1 MeV

15. Doppler Shift Attenuation Method: eg) B(E2): Tanida et al.
gL in a nucleus
B(M1) of L-spin-flip M1 transition
in s-orbit gc
: assuming “weak coupling”
between a L and the core.
R.H. Dalitz and A. Gal, Annals of Phys. 116 (1978) 167.
Doppler Shift Attenuation Method: eg) B(E2): Tanida et al.
PRL 86 (2001) 1982
~100%
7LLi
Modification of gL in nuclear medium?
L-S mixing: C.B. Dover, H. Feshbacj, A. Gal, PRC 51 (1995) 541.
+2--5 % for 4LHe, small for T=0 hypernuclei
K, 2p exchange current: K. Saito, M. Oka, T. Suzuki, NPA 625 (1997) 95.
-7% for 7LLi
“Quark exchange current” in QCM T. Takeuchi, K. Shimizu, K. Yazaki, NPA 481 (1988) 693.
Measurement of mL in a hypernucleus is very difficult => possible via HI

16. Experiment at J-PARC Approved as E13 -> E63 D|gL-gc| Stat. error
pK= 1.1 GeV/c
=1.0 ps
Approved as E13 -> E63
=0.5 ps
DSAM (Doppler Shift
Attenuation Method)
Hypernucleus
in excited state K- p-
Slows down
in material
 =0.1 ps
~ 0.5 ps
tstop ~ 2 ps
in Li2O (2.01 g/cm3)
pK= 1.1 GeV/c
H. Tamura et al., Nucl.Phys. A881 (2012) 310
D|gL-gc|
|gL-gc|
=>
~ 3%
For 35 days for 50kW
Assuming 56k K-/spill for 0.9 GeV/c
176k K-/spill for 1.1 GeV/c
Stat. error
Dt/t = 6% 3+
7/2+
7LLi
1/2+
3/2+
5/2+ 1+
6Li

17. E63 setup K1.1 K1.1 Beam spectrometer Dp/p = 0.042% (FWHM) @1.1 GeV/c
+ multiple scat. effect
E63 setup
Detectors are the same as E13
Almost all of them are ready.
K1.1 beamline will be constructed in the present hadron hall.
For the Li target, we need single-crystal Li2O with a microscopically uniform density.
Succeeded in growing a single crystal rod of Li2O by floating-zone (FZ) method.

18. B(M1) value expected in “ordinary” nuclear physics
Experimental values:
6Li: gc = mN
L: gΛ (free) = ±0.008 mN
=> If weak coupling is OK,
7LLi B(M1)
= 0.334±0.003 mN2
Calculations
5LHe+p+n cluster (Hiyama et al.) a
4He+d+L cluster (Motoba-Bando-Ikeda) b
Shell model (Dalitz-Gal) c
-3.5% from weak coupling
<+5.5% from weak coupling
a H. Hiyama et al., PRC 59 (1999) 2351.
b T. Motoba, H. Bando, K. Ikeda, T. Yamada, PTP Suppl. 81 (1985) 42.
c R.H. Dalitz and A. Gal, Annals of Phys. 116 (1978) 167.
Suggesting that the weak coupling hypothesis holds well.
Better calculation by Hiyama is going on.
4He+p+n+L cluster model with and without L-S coupling
Ab-initio 7-body calculations in future (after the measurement is done)

19. 3. Hyperon-nucleon scattering

20. => BB interaction models using NN and SU(3)f
A new phase of BB interaction studies
phase 1
1960~1980
Sparse YN scattering data (+ limited hypernuclear data)
1980~2010
G-matrix + structure calculations
Precise few body calculations
Previous strategy: Hypernuclear structure data => YN interaction
2010~
High quality hypernuclear /YN scattering data in J-PARC/JLab
BB correlation data from HI collisions
Lattice QCD BB forces
Chiral EFT BB forces
Hyperon puzzle
Multi-messenger (gravity/X-rays/optical) observations of NS
New strategy:
High statistics BB scattering/ correlation data => BB int. in free space
Precise hypernuclear data => BB int. in (high density) medium
=> Confirm from neutron star data => quark matter if not consistent?
=> BB interaction models using NN and SU(3)f
phase 2
=> Improve BB interaction models
phase 3

21. Baryon Baryon interaction by Lattice QCD
Slide by Koji Miwa
Baryon Baryon interaction by Lattice QCD
6 independent forces in flavor SU(3) symmetry
Strong repulsive core
8〇8 = x
J-PARC E40
p (S=0, T=1/2)
(27)
(10*)
(8s)
(10)
(8a)
(1)
+p (S=1, T=3/2)
quark Pauli effect
Flavor singlet (H-Channel)
p (T=0)
J-PARC E42
Recently, lattice QCD qualitatively supports the prediction by the QCM.
There are 6 independent force in SU(3) and 4 new appeared forces show new features.
This channel is included in Sigma+p channel and this channel is included in Sigma-p channel.
In these channel, there is small attractive pocket and large hard core.
On the other hand, these channel (Xi-p channel and H-dibaryon channel) shows weak or attractive core.
By exploring YN and YY interaction, we can obtain the understanding of the generalized BB interaction.
color magnetic
interaction
Lattice QCD calc.
T. Inoue et al.
Prog. Theor. Phys. 124 (2010) 4
Weakly repulsive or attractive Core 21

22. J-PARC E40: S±p Scattering Experiment （Miwa et al.)
Very large repulsive core is predicted in SN (T=3/2,S=3/2) due to quark Pauli effect
S production via p±p→K+S± pS = 0.4 ~ 0.8 GeV/c
Measure ds/dW for S+p, S-p, S-p->Ln
CATCH detector
BGO calorimeter p+
400 mm p K+ S n pS Ep q
Cylindrical
Fiber Tracker
This is the total detector setup including the beamline spectrometer.
For the high rate beam handling at beamline spectrometer, we already developed and installed
two beamline fiber detectors.
These fiber tracker has high efficiency for intense beam and good timing resolution and
we already achieved 12 M/spill p beam at E10 experiment using these detectors.
In this presentation, we focus on the optimization of KURAMA setup and CATCH development status.
Liq H2 target p+
Slide by K. Miwa

23. Slide by K. Miwa
Kinematical matching
S-p → S-p
S-p → Ln

24. Data (angular distribution)
Slide by K. Miwa
Data (angular distribution)
S-p → S-p (0.55 < p (GeV/c) < 0.65)
S-p → Ln (0.55 < p (GeV/c) < 0.65)
expected accuracy (simulation)
expected accuracy (simulation)
Data: Before acceptance and efficiency correction
out of acceptance
very preliminary
very preliminary
Forward peak structure
Rather flat structure

25. 4. Future plans Challenge to the hyperon puzzle

26. How to study density dependence of LN inteaction in matter?
Ab-initio calc. of nuclear masses from NN force => NNN repulsion necessary
Similar YNN (YYN, YYY) repulsive forces?
--- Lack of precise YN scattering /hypernuclear data!
Yamamoto, Furumoto, Rijken et al.
PRC88 (2013) 2, PRC90 (2014)
We should measure
Precise BL data for wide A of L hypernuclei
0.1 MeV accuracy is necessary
NNN determined
from HI collision data
ESC08 only
(no 3B force)
+ 3B/4B repulsion in NNN only
+ 3B/4B repulsion
in NNN +YNN etc.
MPa sL pL dL fL gL
-BL [MeV]
(Mpa)
ハイペロンパズル：
　　高密度の中性子物質では中性子のフェルミエネルギーが高くなり、ハイペロンに転換する方がエネルギー的に得をするので、ハイペロンが混在する。現在知られているバリオン間相互作用によって予想されるハイペロンが混在する高密度核物質の状態方程式では、存在が確認されている2倍の太陽質量の中性子星の重力を支えられずブラックホールになってしまう。これは、現在の核物理の知識に重大な不足があることを示しており、この問題を称して「ハイペロンパズル」という。
ESC:バリオン間相互作用（2体力）
MPa: ESC+MPP+TBA
重い中性子星を支えられる状態方程式を実現する相互作用模型
　　MPP:高密度での斥力
　　TBA：現象論的に導入した3体引力
ECS08 only

27. Extension Plans of J-PARC Hadron Hall
S= -1 Systems
High precision
L hypernuclear spectroscopy
g-ray spectroscopy
weak decays
LN scattering
< 2.0 GeV/c
1.8x108 pion/spill
x10 better Dp/p
S= -2 Systems
5 deg extraction
~5.2 GeV/c K0
Good n/K
LL, X hypernuclei
H dibaryon
< 1.2 GeV/c
~106 K-/spill
HIHR KL
< 2.0 GeV/c
~106 K-/spill
K1.1
< 1.1 GeV/c
~105 K-/spill
K1.8
K1.8BR
K10
TEST BL
<10 GeV/c separated pion, kaon, pbar
~107/spill K-
105 m
High-p
30 GeV proton
<31 GeV/c unseparated 2ndary beams (mostly pions), ~107/spill
COMET
Muon

28. High-Intensity High-Resolution line (HIHR)
Exp. Target
Achromatic
Focus
Dispersive Beam
Mass Slit
High Res.
Spectrometer
Prod. T
(p+,K+) at
Electrostatic
Separator
Intensity: ~ 1.8x108 pion/pulse
(1.2 GeV/c, 50 m, 1.4msr*%,
100kW, 6s spill, Pt 60mm)
Dp/p ~ 1/ (Dm~200 keV)
designed by H. Noumi

29. Physics subjects HIHR < 2 GeV/c, p 2x108/spill
High precision BL of medium and heavy L hypernuclei via (p+,K+)
Neutron-rich L hypernuclei via (p-,K+)
h-nuclei via (p+, p)
h’-nuclei via (p+, p)
tetra neutron and n-rich nuclei via (p-, p+)
K1.1 ( moved from the existing hall)
< 1.2 GeV/c, mass separated, K- 1x106/spill
Lp scattering
Sp scattering including spin-observables
g-ray spectroscopy of L hypernuclei
Weak decays and L hypernuclei
gL and b-decay of L hypernuclei for baryon modification in matter

30. Toward funding Proposal and call for collaboration
arXiv:
Toward funding
arXiv:
Proposal and call for collaboration
Japanese full version published, English version to be published soon.
TDR should be written.
Discussion on physics cases
Int. workshop in March >
Process for funding
Applied for “Master Plan” of Japan Science Council. Should be selected as “high-priority projects”
Should be highly ranked in KEK by Science Advisory Committee -> budget request from KEK
Should be selected in “Road Map” in the government (MEXT)
The government should have enough money
-- Staging approach /Reduction of the cost may be necessary.
We have a good chance.
Please support us!
LOIs in arXiv:

31. 4. Summary
J-PARC hadron hall has operated for 10 years and obtained various new data on strangeness nuclear physics for S=-1 and recently S=-2 nuclear systems.
In g-ray spectroscopy of L hypernuclei, 4LHe data confirmed a large CSB effect, and 19LF data extended our understanding of L hypernuclear structure to a heavier system.
A new g-ray experiment on 4LH for CSB and B(M1) for gL in nuclear medium is being prepared.
A S-p scattering experiment is successfully running. It will get ~102 times more statistics than before.
We will extend the J-PARC Hadron Hall at J-PARC and construct new beamlines, particularly for high-resolution L hypernuclear spectroscopy and LN/SN scattering, to solve the hyperon puzzle.

33. } 7LLi level structure and particle emission thresholds
K- + a + t > 3He + L + t + p-
7Li
4LH
L exchange from a to t
“L” + t
1+;T=0
4LH+3He
19.3
0+;T=0
4LH
-> a + 3LH + p- }
4He + p-
3/2-;T=1
～12
(K-,p-) DL=0, DS=0
a emission
pn→pL substitutional
Substitutional on “t” ～8
3/2-;T=0
1/2+;T=1
3/2+;T=0
3LH+a
6.9
1/2+;T=0
6Li+L
5.6
3LH
5LHe+d
3.9
(K-,p-) DL=1, DS=0
1/2+;T=1
3.88
3He + p-
0.69
3/2+;T=0
1/2+;T=0
7LLi
Eex (MeV)