A search for deeply bound kaonic nuclear states by in-flight 3 He(K-,n) reaction
Search for the Kaonic Bound State K NN - Menu
Transcript of Search for the Kaonic Bound State K NN - Menu
![Page 1: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/1.jpg)
Search for the Kaonic Bound State KbarNN
via 3He(K-, Λp/πΣp)n Reactions
F. Sakuma, RIKEN on behalf of the J-PARC E15
collaboration
YKIS2018b Symposium “Recent Developments in Quark-Hadron Sciences” June 11 - June 15, 2018, Yukawa Institute for Theoretical Physics, Kyoto University
![Page 2: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/2.jpg)
Kaonic Nuclei
2
Y.Akaishi & T.Yamazaki, PLB535, 70(2002). 0 1 2 3
Bound states of nucleus and anti-kaon Predicted as a consequence of attractive KbarN
interaction in I=0
Will provide new insight on KbarN interaction in media
![Page 3: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/3.jpg)
KN πΣ
KbarN interaction - A good probe for low-energy QCD
3
S.Ohnish et al.,PRC93(2016) 025207
KbarN
𝐼𝐼 =12 , 𝐽𝐽𝑃𝑃 = 0−
M. Bazzi et al., (SIDDHARTA Coll.),
Phys. Lett. B704(2011)113
? Calculation on
KbarN amplitude in I = 0
expected to be produced as a Λ(1405)p doorway
![Page 4: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/4.jpg)
Present Status of KbarNN = “K-pp”
4
Chiral Phenomenological
Upper limits were also obtained: • LEPS@SPring8 [Inclusive d(γ, K+π-)X] • HADES@GSI [Exclusive pppΛK+]
π-dK+X
ppK+X
stopped K-
KbarNN is symbolically notated as “K−pp” in this talk
![Page 5: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/5.jpg)
Theoretical Calculations on KbarNN
5
KbarN int. Chiral SU(3) (energy dependent)
Phenomenological (energy independent)
Method
Variational Faddeev Variational Faddeev Barnea,
Gal, Liverts
Dote, Hyodo, Weise
Ikeda, Kamano,
Sato
Yamazaki, Akaishi
Wyceck, Green
Shevchenko, Gal, Mares
Ikeda, Sato
B (MeV) 16 17-23 9-16 48 40-80 50-70 60-95 Γ (MeV) 41 40-70 34-46 61 40-85 90-110 45-80
• KbarN interaction model: – Chiral SU(3) [energy dependent] – Phenomenological [energy independent]
• Calculation method: – Almost the same results
B.E. ~ 20 MeV B.E. ~ 40-70 MeV
![Page 6: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/6.jpg)
“K-pp” Search via Stopped-K-
6
FINUDA@DAΦNE PRL94(2005)212303
6Li+7Li+12C(stopped K-, Λp)
B.E. = 115MeV Γ = 67MeV
2NA followed by FSI? PRC74(2006)025206 PRC82(2010)034608 etc.
AMADEUS@DAΦNE R. Del Grande MESON2018
12C(stopped K-, Λp)
M(K
+p+p
)
Spectrum can be reproduced with 2NA/3NA!
M(K
+p+p
)
![Page 7: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/7.jpg)
“K-pp” Search via pp Collision
7
DISTO@SATURNE PRL104(2010)132502
p + p (Λ + p) + K+ @ 2.85GeV
B.E. = 103MeV Γ = 118MeV
Exp/
Sim
ppp(N*)p(ΛK+)? PRC92(2015)044002
M(K
+p+p
)
HADES@GSI PLB742(2015)242
p + p (Λ + p) + K+ @ 3.5GeV
Spectrum can be reproduced with N*’s
M(K
+p+p
)
![Page 8: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/8.jpg)
“K-pp” Search via d(π-,K+)X
8
M(K
+p+p
)
M(π
+Σ+N
)
E27@J-PARC PTEP(2015)021D01.
d(π-, K+)Yp @ 1.69 GeV/c
B.E. = 95MeV Γ = 162MeV
• Need more statistics • Expect a new experiment with 4π detector @ J-PARC
Yamazaki & Akaishi, PRC76(2007) 045201.
![Page 9: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/9.jpg)
Present Status of KbarNN = “K-pp”
9
Chiral Phenomenological
Upper limits were also obtained: • LEPS@SPring8 [Inclusive d(γ, K+π-)X] • HADES@GSI [Exclusive pppΛK+]
π-dK+X
ppK+X
stopped K-
complicated reactions “in-flight K-” induced reaction
KbarNN is symbolically notated as “K−pp” in this talk
![Page 10: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/10.jpg)
J-PARC E15 Experiment
10
• 3He(in-flight K-,n) reaction @ 1.0 GeV/c – 2NA processes and Y decays can be discriminated kinematically
![Page 11: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/11.jpg)
“K-pp” in 3He(K-,Λp)n
11
![Page 12: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/12.jpg)
Experimental Setup @ K1.8BR
12
![Page 13: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/13.jpg)
13
3He + K- Λ p n Selection
• Λπ-p and p are detected with CDS – A missing neutron is identified
by missing-mass of 3He(K-,Λp)n
• Λpnmiss events are selected by log-likelihood method (lnL) – distance-of-closest-approach
for each vertex – kinematical constraint
E15 collab., arXiv:1805.12275
![Page 14: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/14.jpg)
IM(Λp) vs. cos(θnCM)
14
M(K
+p+p
)
IM(Λp)
cos(θn CM)
Structures around the K-pp threshold can be seen
= bound-state + quasi-elastic
Structures are concentrated in forward-n region
= small momentum-transfer
detector acceptance
E15 collab., arXiv:1805.12275
![Page 15: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/15.jpg)
• Seems to consist of 3 components
– Bound state • centroid NOT depend
on qKn
– Qasi-elastic K- abs. • centroid depends on qKn
– Background • Broad distribution
15
IM(Λp)
qKn =q
Λp
IM(Λp) vs. Momentum Transfer qKn
E15 collab., arXiv:1805.12275
![Page 16: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/16.jpg)
16
IM(Λp)
qKn =q
Λp
IM(Λp) vs. Momentum Transfer qKn
• Fit with 3 components – Bound state
• centroid NOT depend on qKn
• BW*(Gauss form-factor)
– Qasi-elastic K- abs.
• centroid depends on qKn
• Followed by Λp conversion
– Background • Broad distribution
E15 collab., arXiv:1805.12275
* We conduct the fitting in each 2D bin
![Page 17: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/17.jpg)
17
“K-pp” Bound-State
Select 0.35<qKn<0.65 GeV/c – BS and QF are well
separated
E15 collab., arXiv:1805.12275
![Page 18: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/18.jpg)
18
“K-pp” Bound-State
Fit values that reproduce the spectrum: 𝐁𝐁"𝐊𝐊𝐊𝐊𝐊𝐊" = 𝟒𝟒𝟒𝟒 ± 𝟑𝟑 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. −𝟔𝟔+𝟑𝟑 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. 𝐌𝐌𝐌𝐌𝐌𝐌
𝚪𝚪"𝐊𝐊𝐊𝐊𝐊𝐊" = 𝟏𝟏𝟏𝟏𝟏𝟏 ± 𝟒𝟒 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. −𝟗𝟗+𝟏𝟏𝟏𝟏 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. 𝐌𝐌𝐌𝐌𝐌𝐌
𝐐𝐐"𝐊𝐊𝐊𝐊𝐊𝐊" = 𝟑𝟑𝟑𝟑𝟏𝟏 ± 𝟏𝟏𝟒𝟒 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. −𝟏𝟏+𝟏𝟏𝟒𝟒 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. 𝐌𝐌𝐌𝐌𝐌𝐌
𝛔𝛔“𝐊𝐊𝐊𝐊𝐊𝐊” ∙ 𝑩𝑩𝑩𝑩𝚲𝚲𝒑𝒑 = 𝟏𝟏𝟏𝟏 ± 𝟏𝟏 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. −𝟐𝟐+𝟐𝟐 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. 𝛍𝛍𝒃𝒃 𝐬𝐬𝐬𝐬 𝐛𝐛𝐌𝐌𝐛𝐛𝐛𝐛𝐛𝐛 𝐬𝐬𝐭𝐭𝐌𝐌 𝐌𝐌(𝑲𝑲−𝒑𝒑𝒑𝒑)
E15 collab., arXiv:1805.12275
![Page 19: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/19.jpg)
19
“K-pp” Bound-State
𝐁𝐁"𝐊𝐊𝐊𝐊𝐊𝐊" = 𝟒𝟒𝟒𝟒 ± 𝟑𝟑 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. −𝟔𝟔+𝟑𝟑 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. 𝐌𝐌𝐌𝐌𝐌𝐌
𝚪𝚪"𝐊𝐊𝐊𝐊𝐊𝐊" = 𝟏𝟏𝟏𝟏𝟏𝟏 ± 𝟒𝟒 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. −𝟗𝟗+𝟏𝟏𝟏𝟏 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. 𝐌𝐌𝐌𝐌𝐌𝐌
𝐐𝐐"𝐊𝐊𝐊𝐊𝐊𝐊" = 𝟑𝟑𝟑𝟑𝟏𝟏 ± 𝟏𝟏𝟒𝟒 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. −𝟏𝟏+𝟏𝟏𝟒𝟒 𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬. 𝐌𝐌𝐌𝐌𝐌𝐌
• Binding energy: ~50 MeV – Much deeper than chiral-SU(3) based
theoretical predictions • Width: ~100 MeV
– Non-meonic YN decay modes would be dominant
• in theoretical calculations, width is evaluated with mesonic πYN channel
• S-wave form factor: ~400 MeV – K- + 3He reaction would be compact
(~0.5 fm)
E15 collab., arXiv:1805.12275
![Page 20: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/20.jpg)
20
Chiral Phenomenological
For further understandings: Λ(1405) production Λ∗N doorway πΣN decay channel new info. of KbarNN
Present Status of “K-pp” π-dK+X
ppK+X
stopped K-
K-3HenX
![Page 21: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/21.jpg)
Λ(1405) in 3He(K-,πΣp)n
21 21 Λ(1405)
p
K- n 3He Λ(1405)
1 GeV/c p
“K-pp”
“K-pp” formation
“free” Λ(1405)
![Page 22: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/22.jpg)
• Theoretically, “K-pp” is expected to be produced via Λ(1405)+p”K-pp” door-way process – comparison between Λ(1405)p and “K-pp”
production would give us an important information
22
n
Λ(1405)
p
“K-pp” formation “free” Λ(1405)
K- n 3He Λ(1405)
1 GeV/c p
n “K-pp”
Λ
p
ω
Λ(1405)p and “K-pp”
![Page 23: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/23.jpg)
23
K- 3He πΣpn @ E15
• Exclusive measurement of 𝛑𝛑±𝚺𝚺∓𝐊𝐊𝐩𝐩 final state in K-+3He
• Experimental challenge of neutron detection with thin scintillation counter (t=3cm) 10cm
t = 3cm
n detection efficiency ~ 3%
K- n 3He
“X”
n
1 GeV/c Σ
π
π
CDS
p
![Page 24: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/24.jpg)
24
πΣpn Events IM(nπ+) vs MM(π+π-pn) IM(nπ-) vs MM(π+π-pn)
π-Σ+p nmiss π+Σ-p nmiss
nmiss M(Λ)
Σ+ Σ-
nmiss M(Λ)
![Page 25: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/25.jpg)
25
IM(πΣ) vs. cos(θnCM)
M(π
Σ)
M(K
- p) co
s(θ n
-mis
s)
• 𝝅𝝅±𝜮𝜮∓ events are separated using kinematical-fit – Constraints:
• M(Σnπ) • 4-momentum conservation
– Event selection by χ2 probability (0.01<p)
IM(𝛑𝛑±𝚺𝚺∓)
Σ(1385)/Λ(1405)
Λ(1520)
measured unmeasured
constraint: Σ mass
constraint: 4-mom. conservation = n mass constraint
measured measured
measured
measured
![Page 26: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/26.jpg)
26
IM(πΣ) vs. Momentum Transfer qKn
Λ(1520)
IM(𝛑𝛑±𝚺𝚺∓)
q Kn
Σ(1385)/Λ(1405)
• To compare “K-pp” and Λ∗ production CS’s, we select qKn<0.65 GeV/c region – “K-pp” and Λ* signals can be
seen in this region
qKn<0.65 M
(πΣ)
M(K
- p)
IM(Λp)
q Kn
qKn<0.65
cf. 3He + K- Λ p n 3He + K- Λ∗ p n
![Page 27: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/27.jpg)
27
Y* CS (qKn<0.65)
IM(𝛑𝛑±𝚺𝚺∓) M(π
Σ)
M(K
- p)
Λ(1520)
Λ(1405)
Σ0(1385) πΣpn
phases-space
L = 3.0 nb-1
~ 40-80 µb [evaluated from Σ+(1385)π+Λ measurement]
~ 70 µb
~ 130-140 µb Flatté param.:
mR ~ 1418 MeV/c gπΣ ~ 1.9E-1 gKN ~ 1.7E-2
(Σ(1385)πΛ/πΣ : 87.0/11.7%)
![Page 28: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/28.jpg)
28
n
Λ(1405)
p
IM(𝛑𝛑±𝚺𝚺∓) IM(Λp)
“K-pp”Λp “free” Λ(1405)
Large CS of Λ*compared to “K-pp” formation
K- n 3He
Λ(1405)
1 GeV/c p
n “K-pp”
Λ
p ~ 130µb ~ 20µb
Production of Λ(1405)p and “K-pp”
![Page 29: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/29.jpg)
“K-pp” in 3He(K-,πΣp)n
29
Search for “K-pp” πΣN decay channel
![Page 30: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/30.jpg)
30
1. “K-pp” search via Λp channel
2. “K-pp” search via πΣp channel
Non-mesonic channel
Mesonic channel
Two Decay Mode of “K-pp”
FINUDA/DISTO/E27/E15…
NO measurement so far
“K-pp” (𝐽𝐽𝑃𝑃 = 0−) Λ( 12
+) p(1
2
+)
“K-pp” (𝐽𝐽𝑃𝑃 = 0−) π(0−) Σ(12
+) p( 1
2
+)
![Page 31: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/31.jpg)
31
2. “K-pp” search via πΣp channel Mesonic channel
Two Decay Mode of “K-pp”
Theoretically, πΣN decay is expected to be
the dominant channel
S.Ohnish et al.,PRC88(2013)025204
kaon
abs
orpt
ion
prob
abili
ty
of Λ
* N
πΣN
/ΛN
ΛN channel
πΣN channel
NO measurement so far
“K-pp” (𝐽𝐽𝑃𝑃 = 0−) π(0−) Σ(12
+) p( 1
2
+)
![Page 32: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/32.jpg)
32
IM(πΣp) vs. cos(θnCM)
M(π
Σp)
M(K
- pp)
IM(𝛑𝛑±𝚺𝚺∓𝒑𝒑)
cos(
θ n-m
iss)
![Page 33: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/33.jpg)
33
IM(πΣp) vs. Momentum Transfer qKn
q Kn
~ 2 µb
qKn<0.65 GeV/c
qKn<0.65
M(π
Σp)
M(K
- pp)
IM(𝛑𝛑±𝚺𝚺∓𝒑𝒑)
![Page 34: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/34.jpg)
34
IM(Λp)
~ 20µb
~ 2µb
Λp decay is dominant below M(K-pp)
IM(𝛑𝛑±𝚺𝚺∓p) qKn<0.65 GeV/c
![Page 35: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/35.jpg)
35
IM(𝛑𝛑±𝚺𝚺∓) vs. IM(𝛑𝛑±𝚺𝚺∓𝒑𝒑)
M(π
Σp)
M(K
- pp)
M(πΣ)
M(K-p)
Λ(1405)
QF
Small phase-space of “K-pp”πΣN
K- 3He
1 GeV/c
n
Λ(1405)
p
n p
p
IM(𝛑𝛑±𝚺𝚺∓𝒑𝒑)
IM(𝛑𝛑
±𝚺𝚺∓
)
![Page 36: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/36.jpg)
Conclusions
36
• We have observed a resonance peak below the K-pp threshold in 3He(K-,Λp)n, “K-pp” – Binding energy: ~50 MeV – Width: ~100 MeV – S-wave form factor: ~400 MeV
• Λ(1405) was clearly observed in 𝛑𝛑±𝚺𝚺∓p
nmiss final state – Large CS of Λ*compared to “K-pp” formation
• Weak structure below the K-pp threshold
is seen in IM(𝛑𝛑±𝚺𝚺∓p) – Non-meonic YN decay modes would be dominant
need further investigation of “K-pp” πΣN
E15 collab., arXiv:1805.12275
need theoretical feedbacks
![Page 37: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/37.jpg)
What we have to do next • More quantitative studies of the “K-pp”
– JP • Angular distributions of “K-pp”Λp and Λπ-p are consistent
with S-wave, in current statistics – πΣp decay mode
• Due to phase-space, or, detector acceptance(?) • Series of the kaonic nuclei searches:
– “K-ppn” via [K- + 4He], “K-ppnn/K-pppnn” via [K- + 6Li], etc. – “K-K-pp” via [pbar + 3He annihilation]
37
We need a 4π detector system with γ/n sensitive detectors
![Page 38: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/38.jpg)
Thank You! J-PARC E15 Collaboration
38
![Page 39: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/39.jpg)
Spares
39
![Page 40: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/40.jpg)
40
![Page 41: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/41.jpg)
A Theoretical Interpretation of E15
41
Chiral unitary approach
M[K
+p+p
]
KbarNN bound-state
quasi-elastic kaon
scattering
Sekihara, Oset, Ramos, arXiv:1607.02058
Uncorrelated Λ(1405)p
state
M[K
+p+p
]
B=16MeV Γ=72 MeV
Opt.A (Watson) Opt.A (Watson)
![Page 42: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/42.jpg)
KbarNN or NOT? --- Other Possibilities
42
• Λ(1405)N bound state – loosely-bound system, I=1/2, Jπ=0- – various decay modes, ΛN/ΣN/πΣN
• πΛN-πΣN dibaryon
– structure near πΣN threshold – I=3/2, Jπ=2+ no Λp decay (I=1/2)?
• Double-pole KbarNN – loosely-bound KbarNN, & – broad resonance near the πΣN threshold πΣN decay
• Partial restoration of Chiral symmetry – enhancement of the KbarN interaction in dense nuclei
H. Garcilazo, A. Gal, NPA897(2013)167.
T. Uchino et al., NPA868(2011)53.
A. Dote, T. Inoue, T. Myo, PTEP (2015) 043D02.
S. Maeda, Y. Akaishi, T. Yamazaki, Proc. Jpn. Acad., B89(2013)418.
A structure near KbarNN threshold
A structure near πΣN threshold
![Page 43: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/43.jpg)
3He(K-,Λp)n: Decay Channel
43 Γ(Λp) > Γ(Σ0p) !?
Λp
Λp
Λp
Σ0p
Σ0p
Σ0p
slic
ed
Λp~Σ0p
πYN
M[K+p+p]
Σ0p~πYN
![Page 44: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/44.jpg)
44
![Page 45: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/45.jpg)
45
![Page 46: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/46.jpg)
46
![Page 47: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/47.jpg)
47
![Page 48: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/48.jpg)
48
DATA
![Page 49: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/49.jpg)
49
Neutron ID with CDS
dE vs. 1/β dE-cut dependence
5MeVee < dE
1.372 < 1/β (pn<1GeV/c)
Neutron can be identified with CDS
• π+π-p events (3 tracks) in CDS with 4 CDH hits are selected • a CDH hit with CDC-veto (outer-layer) is applied to identify the “neutral hit”
![Page 50: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/50.jpg)
50
Λ*pn Events IM(nπ+π-) vs MM(π+π-pn)
Λ(1405)p nmiss Λ(1520)p nmiss M(n) M(Λ)
M(Λ(1405))
M(Λ(1520))
![Page 51: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/51.jpg)
51
Y* CS (qKn<0.65)
IM(𝛑𝛑±𝚺𝚺∓) M(π
Σ)
M(K
- p)
Λ(1520)
Λ(1405)
Σ0(1385)
πΣpn phases-space
IM(𝛑𝛑+𝚲𝚲)
Σ+(1385)
𝝅𝝅+𝜦𝜦n nmiss final state
πΛpn phases-space
M(π
Λ)
M(K
- p)
we assume Σ0(1385) CS at 1.0 GeV/c to be: σ(Σ*0) ~ 1-2*σ(Σ*+)
K- + 3He Σ0(1385) + p + n: ~ 40-80 µb (assumption) K- + 3He Λ(1405) + p + n: ~ 130 µb K- + 3He Λ(1520) + p + n: ~ 70 µb
~ 40 µb L = 3.0 nb-1
𝝅𝝅𝚺𝚺p nmiss final state
![Page 52: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/52.jpg)
52
IM(πΣp) vs. Momentum Transfer qKn
q Kn
~ 2 µb
qKn<0.65 GeV/c
qKn<0.65
M(π
Σp)
M(K
- pp)
IM(𝛑𝛑±𝚺𝚺∓𝒑𝒑)
Corresponding to Λ(1405) mass-region
![Page 53: Search for the Kaonic Bound State K NN - Menu](https://reader031.fdocuments.net/reader031/viewer/2022012506/6181c119efa233392f1f04d3/html5/thumbnails/53.jpg)
detector acceptance
53
Detector Acceptance: Λp vs. πΣp
detector acceptance
𝛑𝛑±𝚺𝚺∓𝒑𝒑
𝚲𝚲𝒑𝒑
M(K
- pp)
M(π
Σp)
• Detector acceptance is different between Λp and πΣp – At cosθn~1:
• Λp: flat acceptance • πΣp: limited acceptance
below the threshold
cf. 𝛑𝛑±𝚺𝚺∓𝒑𝒑𝒏𝒏-PS MC w/ detector acceptance
M(K
- pp)
M(π
Σp)
DATA
DATA MC