Experimental Progress inStrangeness Nuclear Physics
— Report from Group A01&A02 —
T.Takahashi on behalf of Group A01 & A02(KEK IPNS/J‐PARC Center)
at NSMAT2016 (2016 Nov. 21)
Contents
• Introduction• Goal of Group‐A projects• Knowledge on Hyperon Potential & Interaction in 2012
• Experimental Progress in SNP• Progress – 5 physics results • Detectors under construction
• Hyperon Spectrometer & CATCH
• Summary
2016/11/21 NSMAT2016 2
Introduction
2016/11/21 NSMAT2016 3
r
Joint project between experiments, observations, theories
⇒ properties of neutron matter
Theories
High Int. proto acc.J-PARC
⇒ n-star radius
Unstable beam factoryRIBF
Strangeness nuclear physics
X-ray observatoryASTRO-H
Understand structure of n-star
“Science of Matter based on quarks”
Cold atoms
n-rich nuclei
⇒ Interaction of hyperons
X-ray astronomy
World-best two accelerators and
X-ray satellite
Nuclear matter EOS
2016/11/21 NSMAT2016 4
Expected 12C spectrum
5
6ΛΛHe
4He
t
Ξ-
p
π-
ΛHe
10μm500
10
5
6He hypernucleus
hypernuclear spetrocopy(Unique in the world)
nuclei from emulsion(Unique in the world, 10 times improved)
N int.
→ EOS of high density matter
A01: Interactions of multi‐strangeness systems
Determine hyperon mixing in the inner core(> 30)
E05
Baryon fractionfr
actio
n
Nakazawa、SumihamaH.takahashi
Takahashi, Naruki
Sato, Imai,Takahashi,Naruki
int.
Peak in invariant mass
correlation(Unique in the world)
(density)
?
N→int. n
H dibaryon?
Hyperon spectrometer
TPC, S.C.magnet
E07
E42
2016/11/21 NSMAT2016 5
coherent couplingn n
n n
(1) +p scattering(unique)Miwa, Tamura
‐> n ( p) int.=> exists in n‐star or not
(2a) spectroscopy of hypernuclei
(Unique method ) Koike, Tamura‐> Details of N, NN int.(2b) n‐rich hypernuclei(Unique method) Sakaguchi, Ajimura, Fukuda
‐>nn int. in n‐rich environment=> Fraction of in n‐star
(3) K‐ nuclear bound states Outa,, Suzuki
‐> KbarN int. in matter=> K condensation in n star?
A02: Strangeness in n-rich matter
E10
E15, E27
Determine hyperon mixing in =2~30region where hyperons begin to appear
E40
E13
frac
tion
ρ
n
p
n attractive
n repulsive
?
p
p/n
LH2 targ
Fiber tr
Ca
PiID co
Forward calorimeter
Ultra-fast (x100)Tracking detector
Using MPPC
Sattered proton detector
K-
p p2016/11/21 NSMAT2016 6
Hyperon Potential & Interactionsknowledge in 2012 (at Kick-off sympo.)
:U = 30 MeV in normal (NZ) matter at 0U ? in neutron‐rich matter
(, , ) :N int. is repulsive but how much?
( , ) : nucleus is not well establishedU = 14 MeV ? (12Be) B = 2.6 MeV ? (+14Ntwin ‐nucleus)
interaction:B = 0.67 ± 0.17 MeV from NAGARA event
systematic data (A‐dependence)YY:N:
Group‐A02(S=1)
Group‐A01(S=2)
to be established
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Progress of SNP (2012 - present)
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Progress (1) Discovery of Ξ nucleus
In the test application of Overall Scanning Method, which is under R&D for incoming E07 Experiment, to the emulsion sample irradiated before, we found the event in which is deeply bound in 14N. This is the first evidence of ‐nucleus
In the test application of Overall Scanning Method, which is under R&D for incoming E07 Experiment, to the emulsion sample irradiated before, we found the event in which is deeply bound in 14N. This is the first evidence of ‐nucleus
+ 14N→ 10Be(#1) + 5He(#2)
Newspaper(2015/1/19)
Binding energy of
> 1.03±0.18 MeV c.f. 0.17 MeV(atomic orbit)3.87±0.21 MeV if 10Be is in ground state.
In E07, ~100 double‐strangeness events will be observed. ⇒ detailed information on S=‐2 interaction
In the R&D of E07Discovery of ‐Nucleus for the first time – KISO Event –
Attractive N interaction has been established.
PTEP 033D02 (2015)
⇒ K.Nakazawa
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Start of E07 (Emulsion exp.) at K1.8
KURAMA (260msr) installed at K1.8mom
entum [G
eV/c]
K
K
Beam was exposed to the 18/118 emulsion stacks in June 2016.
⇒ K.Nakazawa⇒ S.Hayakawa & M.Fujita (poster)
2016/11/21 NSMAT2016 10
Progress (2): 12C(K-,K+) Pilot data
(K,K+) Missing mass spectroscopy using SKSM 6 MeV (FWHM)
Missing Mass (GeV)1.3 1.3051.311.3151.321.3251.331.3351.341.3451.35
Cou
nts /
0.5
MeV
0
100
200
300
400
500
) at 1.8 GeV/c+, K-Missing mass p(K ) at 1.8 GeV/c+, K-Missing mass p(K
previous data at BNL‐AGSM 14 MeV(FWHM)
P.Khaustov et al., PRC61 (2000)054603 ⇒ S.Kanatsuki2016/11/21 NSMAT2016 11
Progress (3): Neutron-rich Λ nuclei— No observation of 6ΛH (J-PARCE10) —
t + 2n + 0.0
4H + 2n
‐2.04
5H +
Glue likerole of
coherentcoupling
6H
Y.Akaishi et al. Phys.Rev.Lett.84(2000)3539
‐2.31
FINUDA
M.Agnello et al., FINUDA CollaborationPRL 108 (2012) 042501
6Li ( , K+ ) X
H.Sugimura et al. PLB729(2014)39
No peak structure in bound/resonance region
U.L. 1.2nb/sr (90%C.L.)
⇒ R.Honda2016/11/21 NSMAT2016 12
Progress (4) Charge Symmetry Breaking in ΛN interaction
‐ray spectroscopy at J‐PARC E13
coun
ts/8 keV
E [MeV]
4He(K,) 2015 Apr.‐MayJune
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Progress (4) Charge Symmetry Breaking in ΛN interaction
• Large CSB of 1+‐0+ level spacing• spin‐dependent CSB
• 1+ : small/no• 0+ : large
• effect of N‐N mixing ?
T.O.Yamamoto et al. PRL115 (2015) 22501
decay spectroscopyat MANI‐C2.12±0.01stat.±0.09syst.
A.Esser et al. PRL114(2015)232501
Importance of Three‐Body Force
⇒ T.O.Yamamoto & S.Nagao
⇒ S.Yang , M.Nakagawa( other E13 results )
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Progress (5) Observation of “K-pp”
J‐PARC E27 @K1.81405) doorway production
at p=1.69 GeV/cd → K+XX → p → p→ pp
Mx
Y.Ichikawa et al. PTEP 2015 21D01
B = 95 (stat.) (syst.) MeV
= 162 (stat.) (syst.) MeV
+1817
+3021
+8745
+6678
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Progress (5) Observation of “K-pp”
J‐PARC E15 @K1.8BRK 3He → X n at pK = 1.0 GeV/cX → p
E151st
E152ndY.Sada et al. PTEP (2016) 051D01
⇒ H.OutaM[K+p
+p]
M[+
+N]
Two structures around M[K+p+p]!?
2013 May
2015 Nov.‐Dec.
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Large-Acceptance Hyperon Spectrometerfor H-dibaryon Search (E42)
K C (diamond) → K+ H XH → / p / p → p
KURAMA
K1.8BS
Hyperon Spectrometer
• large acceptance• high‐rate tolerance
(K) beam 1MHz• good invariant massresolution 1MeV
Hyperon Spectrometer (HS) S.C. Helmholtz magnet
1.0 T TPC with 3 GEM layers
GET readout system TOF hodoscopes .... Target inside TPC
⇒ J.K.AhnS.H.Kim (poster)2016/11/21 NSMAT2016 17
Hyperon Spectrometer- S.C. Helmholtz magnet -
Max field: 1.5 T @ 99.9AField region: 500mmφ×500mmWeight: 10 tonConductive cooling by 2 GM cryocoolers
All of necessary items (cryocoolers, monitors, power supply etc.) will be ready mid‐Dec. Then we will start cooling / excitation tests.
KEK‐Tsukuba Campus (ERL building)
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Hyperon Spectrometer - TPC -Full set of TPC was fabricatedand arrived at J‐PARC (Oct.2016)
Beam test at ELPH‐Tohoku, Nov.7‐10
The first cosmic‐ray event
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⇒ S.H.Kim (poster)
CATCH for Σp Scattering Exp.⇒ K.Miwa
()
()
p = n interaction
Liq.H2
Requirements• Large acceptance for scattered proton• High rate tolerance
beam rate 10MHz• Kinematical identification of p scattering
energy and direction
Cylindrical Fiber Tracker (CFT)4 layers for & 4 layers for UVMPPC readout
BGO calorimetershaping amplifier
+ flash ADC readout2016/11/21 NSMAT2016 20
CATCH and its first application
p‐d elastic scattering and break‐up reaction experiment using CATCH will be performed at CYRIC‐Tohoku Jan.16‐17, 2017
⇒ Y.Akazawa
Cylindrical Fiber Tracker (CFT)
BGO calorimeter
Construction of CATCH was just completed.
1st application to physics experiment
Beam power & K- intensity (K1.8BL)
@38.6kW ( Nov. 2014 )duration: 5.51 sec.spill length: 2.0‐2.1 sec.4.43× 1013 ppp
(optimal condition)
38.6kW(Nov. 2014)
41.5kW(Dec. 2014)
(42kW)(June 2015)
53 kw x (s. f.)(next)limited by T1
24kW(Apr.2014)
33kW(June 2014) • Design of 80kW
target was finished• R & D of >100kW
target is underway
2016/11/21 NSMAT2016 22
Summary nuclei have been established.
KISO event ( 14N ) 12C(K‐,K+) missing mass spectrum with M6MeV
➡ potential / N interaction is attractive. in (neutron‐rich) nuclei
No observation of 6H ↔ Prediction of Theory Large C.S.B. in 4He / 4H system
➡ suggests importance of T.B.F. via N‐N mixing Kpp bound state exists !New detectors have been developed / under construction for near future experiments Hyperon Spectrometer , CATCH
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