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Spectroscopy of Hyperon Resonances and Related Program at J-PARC
Hiroyuki NoumiRCNP, Osaka Univ./IPNS, KEK
YSTAR2016@JLab, Nov. 16-17, 2016
Contents
• Hyperon resonances below KbarN threshold
– KbarN interaction
– L(1405) : a dynamically generated meson-baryon state
– A role of low energy Kbar beams
• Experiment at the J-PARC K1.8BR BL
• Further studies on L(1405)
– Production rate and Form factor
– L(1405) production in Hard process: quark counting
2
L(1116), 1/2+
L(1405), 1/2-
L(1520), 3/2-
S*(1385), 3/2+
S(1192), 1/2+
KN(1432)
-27 MeV
Λ(1405) : 1405.1+1.3-0.9 MeV (PDG)
JP = ½-, I = 0, ML(1405)< MKbarN , lightest in neg. parity baryons
J. Esmaili et al: pS IM Spec. of Stopped K- on 4He
R.H. Dalitz et al: pS IM Spec. in K-p→ππΣ w/ M-matrix
M. Hassanvand et al: pS IM Spec. of pp→K+pS
L(1116), 1/2+
L(1405), 1/2-
L(1520), 3/2-
S*(1385), 3/2+
S(1192), 1/2+
KN(1432)
-27 MeV
Λ(1405) : Double pole?JP = ½-, I = 0, ML(1405)< MKbarN , lightest in neg. parity baryons
KNpS
Chiral Unitary Model: D. Jido et al., NPA725(03)181
L(1116), 1/2+
L(1405), 1/2-
L(1520), 3/2-
S*(1385), 3/2+
S(1192), 1/2+
KN(1432)
-27 MeV
Λ(1405) : Need more data?JP = ½-, I = 0, ML(1405)< MKbarN , lightest in neg. parity baryons
CLAS collaboration: PRC87, 035206 HADES collaboration: PRC87, 025201
𝛾𝑝 → 𝐾+𝜋−Σ+, 𝐾+𝜋0Σ0, 𝐾+ 𝜋+Σ−
𝑝𝑝 → 𝐾+𝑝𝜋−Σ+, 𝐾+ 𝑝𝜋+Σ−
𝜋−Σ+
𝜋+Σ−
Still L(1405)?
• KbarN int. and its pole position are still unclear.
– Basic information on Kaonic Nuclei (→ H. Ohnishi)
• Not yet demonstrated if it is a molecular state.
– To establish it as an exotic state
• Hadron Picture in excited states
• New question related to classification in CQM
– Formation probability in hadronization
• ExHIC (Phys.Rev. C84 (2011) 064910)
6
Important role of Low Energy Kbar Beams
0
100
200
300
400
500
600
700
800
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Y* -
YG.S
.[M
eV]
MQ [GeV/c2]
Lambda Baryons (P-wave)
7
s c
non-rel. QM:H=H0 +Vconf +VSS+VLS+VT
r-l mixing (cal. By T. Yoshida)
Sc(1/2+)
Sc*(3/2+)
Lc(2595, 1/2-)Lc(2625, 3/2-)
Lc or Sc (2765, ??)
Lc(2880, 5/2+)
Lc(2940, ??)
Lc(GS)
L(1520, 3/2-)
S(1/2+)
L(1/2+)
S*(3/2+) L(1405, 1/2-)
L(1830, 5/2-)
L(1690, ??)L(1670, 1/2-)
L(GS)
l
r
b
r
Sb(1/2+) Sb
*(3/2+)
Lb(5920, 3/2-)Lb(5912, 1/2-)
Lb(GS)
Q
l
r
?
T. Yoshida et al.,Phys. Rev. D92, 114029(2015)
Still L(1405)?
• KbarN int. and its pole position are still unclear.
– Basic information on Kaonic Nuclei (→ H. Ohnishi)
• Not yet demonstrated if it is a molecular state.
– To establish it as an exotic state
• Hadron Picture in excited states
• New question related to classification in CQM
– Formation probability in hadronization
• ExHIC (Phys.Rev. C84 (2011) 064910)
8
Important role of Low Energy Kbar Beams
9
Spectroscopic Study of Hyperon Resonancesbelow KbarN Threshold via the (K-,n) Reaction on Deuteron
the E31 collaboration
S. Ajimura1, H. Asano1, G. Beer2, C. Berucci4, M. Bragadireanu12, P. Buehler4, L. Busso5, M. Cargnelli4, S. Choi3,
C. Curceanu8, S. Enomoto14, D. Faso5, H. Fujioka13, Y. Fujiwara12, T. Fukuda11, C. Guaraldo8, T. Hashimoto9,
R. S. Hayano13, T. Hiraiwa1, M. Iio15, M. Iliescu8, K. Inoue1, N. Ishibashi7, Y. Ishiguro14, T. Ishikawa13, S. Ishimoto15,
T. Ishiwatari4, K. Itahashi9, M. Iwai15, M. Iwasaki9,10, S. Kawasaki1, P. Kienle16, T. Kim10, H. Kou10, Y. Ma9, J. Marton4,
Y. Matsuda13, Y. Mizoi11, O. Morra5, T. Nagae14, H. Noumi1,15, H. Ohnishi9, S. Okada9, H. Outa9, K. Piscicchia8,
M. Poli Lener8, A. Romero Vidal8, Y. Sada1, A. Sakaguchi7, F. Sakuma9, M. Sato9, M. Sekimoto14, H. Shi8, K. Shirotori1,
D. Sirghi8,12, F. Sirghi8,12, S. Suzuki15, T. Suzuki13, H. Tatsuno8, M. Tokuda10, D. Tomono1, A. Toyoda15, K. Tsukada17,
O. Vazquez Doce8,18, E. Widmann4, K. Wuenschek4, T. Yamaga1, T. Yamazaki9,13, K. Yoshida7, H. Yim19, J. Zmeskal4 .
1. Research Center for Nuclear Physics, Osaka University, Japan
2. University of Victoria, Canada, 3. Seoul National University, South Korea
4. Stefan Meyer Institut fur subatomare Physik, Austria, 5. INFN Sezione di Torino, Italy , 6.Universita’ di Torino, Italy
7. Osaka University, Japan, 8. Laboratori Nazionali di Frascati dell’INFN, Italy, 9. RIKEN, Japan
10. Tokyo Institute of Technology, Japan, 11. Osaka Electro-Communication University, Japan
11. National Institute of Physics and uclear Engineering, IFIN HH, Romania
13. University of Tokyo, Japan, 14. Kyoto University, Japan
15. High Energy Accelerator Research Organization (KEK), Japan, 16. Technische Universitat Munchen, Germany
17. Tohoku University, Japan, 18. Excellence Cluster Universe, Technische Universitat Munchen, Germany
19. Korea Institute of Radiological and Medical Sciences (KIRAMS), South Korea
measuring an S-wave ഥ𝐾𝑁 → πΣ scattering below the ഥ𝐾𝑁threshold in the d(K-,n)pS reactions at a forward angle of n.
E31 aims at:
ID’s all the final states to decompose the I=0 and 1 ampl’s.
K-
d
n
ഥ𝑲 𝝅∓,𝟎
𝜮±,𝟎𝑵
𝑵
𝝅±𝚺∓ I=0, 1 L(1405) (I=0, S wave), non-resonant[I=0/1](S(1385) (I=1, P wave) to be suppressed)
𝝅−𝚺𝟎
[𝝅−𝚲]I=1 non-resonant (S(1385) to be suppressed)
d(K-,p)p-S0 [p-L]
𝝅𝟎𝚺𝟎 I=0 L(1405) (I=0, S wave), non-resonant
Ushiwaka
CDS
D5
NCPC
K-n
d L(1405)
n
1 GeV/c ~1.25 GeV/c
~0.25 GeV/c
Cylindrical Detector System(Solenoid Field 0.7T)
K- Beam Spectrometer(K1.8BR-D5)
Beam Sweeper(Ushiwaka)
Neutron
Counter (NC)
TOF~15m
ProtonCounter (PC)
11
Experimental Setup for E31
Sp
p
CDCT0
BHDBLC2
BLC1
BPDBPC
CDH
Schematic Drawings of Detectors
• Event topology of 𝑑 𝐾−, 𝑛 𝑋𝜋±Σ∓
12
𝚺−(𝚺+)
NC
CDS𝝅−(𝝅+)
𝐧𝐊−
~15 m
CDC
CDC
n
BPD
T0
Solenoid mag.
𝝅+(𝝅−)
13
Particle ID (CDS)
𝝅+
𝝅−
𝒑
𝑲−
E31 Run Summary
14
E31 run
Beam Power
Beam Time
Executed/Proposed
pre May 2015
27 kW 2.2d ~5%
1st May-June 2016
43 kW ~7d ~30%
2nd Spring? 2017
45 kW(Expected)
~18(+2)d(request)
100%
𝑑 𝐾−, 𝑛𝜋+𝜋− 𝑛𝑚𝑖𝑠𝑠𝑖𝑛𝑔
15
Gated“𝑛” 𝑛𝜋0
Missing Mass of 𝒅 𝑲−, 𝒏𝝅+𝝅− [𝐆𝐞𝐕/𝒄𝟐]
p +
nS +
K -
p -
“n”NC
CDS
p -
nS -
K -
p +
“n”NC
CDS
16
𝑑 𝐾−, 𝑛𝜋+𝜋− "𝑛“ samples contain…
S +S -
K 0p +
n
S +K -
p -
p -
n
S -K -
p +
p +
nK 0K -
p -
S - S +K 0
p +
nS +
K -
p -
“n”
Background Events
Signal Events
𝑑 𝐾−, 𝑛 𝑋𝜋±Σ∓
p -
nS -
K -
p +
“n”
𝑑 𝐾−, 𝑛 𝑋𝜋±Σ∓ Spectrum
17
Missing mass spectrum of the 𝑑 𝐾−, 𝑛 𝑋𝜋±Σ∓ reaction
K0 and Sdecay events have been excluded.
𝐾−𝑝
𝜋+Σ−/𝜋−Σ+ Mode separation(template fitting)
18
S +
S -
pS missing mass [GeV/c2]
Co
un
ts/5
MeV
𝜋+Σ−/𝜋−Σ+ Mode (𝐼 = 0, 1)
19
𝜋−Σ+
𝜋+Σ−++
𝑑𝜎
𝑑Ω𝜋±Σ∓ =
1
3𝑓𝐼=0
2 +1
2𝑓𝐼=1
2 ±6
3𝑅𝑒(𝑓𝐼=0𝑓𝐼=1
∗ )𝑑2𝜎
𝑑Ω𝑑𝑀𝜋Σ
(Arb
itra
ry U
nit
)
𝜋+Σ−/𝜋−Σ+ Mode Average
20
𝑑𝜎
𝑑Ω𝑎𝑣 =
1
3𝑓𝐼=0
2 +1
2𝑓𝐼=1
2𝑑2𝜎
𝑑Ω𝑑𝑀𝜋Σ
(Arb
itra
ry U
nit
)
𝑑 𝐾−, 𝑝 𝑋𝜋−Σ0 Mode (𝐼 = 1)
21
Σ0
Σ0
Λ
Λ
p -
pS 0K -
p -
From 𝑑 𝐾−, 𝑝𝜋−𝜋− "𝑝𝛾" sample
𝑑 𝐾−, 𝑝 𝑋𝜋−𝜦
𝑑 𝐾−, 𝑝𝜋−𝜋− "𝒑"
22
𝜋+Σ−/𝜋−Σ+ Average (𝐼 = 0, 1)V.S. 𝜋−Σ0 Mode (𝐼 = 1)
1
2× 𝜋−Σ0 ~
1
2𝑓𝐼=1
2𝑑𝜎
𝑑Ω𝑑𝑀𝜋Σ
(Arb
itra
ry U
nit
)
1
2× 𝜋+Σ− + 𝜋−Σ+
~1
3𝑓𝐼=0
2 +1
2𝑓𝐼=1
2
• The I=0 amplitude seems dominant.
Remarks of E31 1st Run
• Structures below and above the ഥ𝐾𝑁 threshold are observed in 𝑑 𝐾−, 𝑛 𝑋𝜋±Σ∓
– Interference btw I=0 and 1.
• Pure I=1 channel, 𝑑 𝐾−, 𝑝 𝑋𝜋−Σ0, is observed.
– I=0 amp. seems dominant in 𝜋±Σ∓ modes, assuming similarity of the reaction mechanism among 𝑑 𝐾−, 𝑛 𝑋𝜋±Σ∓ and 𝑑 𝐾−, 𝑝 𝑋𝜋−Σ0.
24
In E31 2nd Run
• To measure a Pure I=0 channel, 𝑑 𝐾−, 𝑛 𝑋𝜋0Σ0
25
𝚺𝟎
NC
CDS𝝅−
𝐧𝐊−
~15 m
CDC
CDC𝜋0
γ
p
BPD
T0
Solenoid mag.
𝑑 𝐾−, 𝑛 𝑋𝜋0Σ0 mode (I=0)
26
s~3.7 MeV/c2
Λ
↳ 𝛾Λ↳ 𝑝𝜋−
Invariant Mass of 𝒑𝝅− [𝐆𝐞𝐕/𝒄𝟐]
C𝐨𝐮𝐧𝐭𝐬
p -
nS 0
K -
g
p
p0BPD
T0
π0
π0γ
(2π)0
MM of 𝐝 𝐊−, 𝒏𝒑𝝅− 𝑿 [𝐆𝐞𝐕/𝒄𝟐]C𝐨𝐮𝐧𝐭𝐬
Promising to measure with higher statistics in the 2nd Run
Further studies on L(1405)• Angular dependence of 𝑑 𝐾−, 𝑛 𝑋(𝜋Σ)0
– “Sticking probability” of ഥ𝐾 to a residual 𝑁
27
𝐼(𝑞; 𝑏0) = | 𝑓(𝑏0) 𝑗0(𝑞𝑟/ℏ) 𝑖 |2
𝑓 𝑏0 ~𝑁exp(−𝑟2/𝑏02): S wave final state
𝑞: mom. transfer (angular dependent)
The larger 𝑏0, the steeper angular dependence.
-0.4-0.200.20.40.60.811.2
-0.4-0.2
00.20.40.60.8
11.2
0 1 2 3 4 5
exp
(-r2
/b0
2)
j 0(q
r)
r [fm]
q=0.25 GeV/c
q=0.4 GeV/c
b0=2 fm
b0=1fm
b0 1fm 2fm
I (q=0.25 GeV/c) 0.69 0.3
I (q=0.4 GeV/c) 0.42 0.12
ratio 0.6 0.4
Further studies on L(1405)
• L(1405) production in Hard process (at large s, t) :
– quark counting rule: 𝑑𝜎/𝑑Ω|𝜃=90𝑜~ 1/𝑠𝑛−2
28
H. Kawamura, et al.PRD 88, 034010 (2013)
𝜋− + 𝑝 → 𝐾− + Λ(1405)
29
High-res., High-momentum Beam Line
30 GeV
proton beam
Production
Target
Pion BeamUp to 20 GeV/c
Spectrometer
T1
• High-intensity secondary Pion beam (unseparated)– 1.0 x 107 pions/sec @ 20GeV/c
• High-resolution beam: Dp/p~0.1%
K+
p-
ps-
decayp(p+)
RICH
ITOF
FiberTracker
DCDC
DCTOF
H2 TGT
In Summary
• Low energy Kbar beams are useful to study hyperon resonances.
– In particular, they play important roles on further studies of L(1405) and the KbarN.
• It is complimentary to other beams, such as high-momentum hadron beams at J-PARC.
30