Workshop on Progress on J-PARC hadron physics in 2014
30 Nov.-2 Dec., 2014

Experiments of charmed baryons atJ-PARC
H. Noumi (RCNP, Osaka University)
2 December, 2014

Contents:
1. Introduction
2. Charmed Baryon Spectroscopy via (p-,D*-)
Mass Spectrum, Production, and Decay

3. Detector R&D
4. Summary1How are hadrons formed?
Hadron?
Current
Quark
2

How are hadrons formed?
Hadron“Building Block”
Constituent Quark
Current
Quark
3

How are hadrons formed from quarks?
L(1405)XYZ
Θ+New Hadrons“Building Block”
Constituent Quark
CurrentQuark
4

How are hadrons formed from quarks?
New Hadrons“Building Block”

Constituent
Quark

5

How are hadrons formed from quarks?
New Hadrons“New Building Blocks”

Constituent
Quark

Diquark

Hadrons66

Hadrons“Characteristic Quasi-Particle”

Constituent
Quark

Diquark

Hadrons7

What we can learn frombaryons with heavy flavors
qqqq
q

Q

• Quark motion of “qq” is singled out by a heavy Q• Diquark correlation• Level structure, Production rate, Decay properties• Properties are expected to depend on a Q mass.

8

Hadron Spectroscopy in H.E. Exp.
• e+e-(Belle), pp(LHCb), RHI(RHIC/LHC), …
– Invariant Mass Spectroscopy
mass reconstructed from F. S. Particles• Production from Vacuum/QGP– 𝑒 + 𝑒 − → 𝑞 𝑞 → 𝑞 𝑞 + 𝑞 𝑞 , 𝑞𝑞𝑞+𝑞 𝑞 𝑞 , …
𝑞𝑞 [𝑞𝑞] + 𝑞 𝑞 , …
– 𝑔𝑔 → 𝑞 𝑞 → ……
– QGP → 𝑞 𝑞, 𝑞𝑞𝑞, …
[𝑞𝑞]𝑞, [𝑞 𝑞][𝑞𝑞], [𝑞𝑞]𝑞𝑞𝑞, 𝑞 𝑞𝑞 [𝑞𝑞], …
9

Hadron Spectroscopy at J-PARC• Unique approach– Missing Mass Spectroscopy in M-B collisions.
𝑞 𝑞 + 𝑞[𝑞𝑞] → 𝑞 𝑄 + 𝑄[𝑞𝑞]in addition to mass, width, and spin/parity
Production Cross Section
Decay Property : Decay Branching Ratios… reflect Quark-Diquark config. of Baryons→ baryons with heavy flavors
10

High-res., High-momentum Beam Line• High-intensity secondary Pion beam
– >1.0 x 107 pions/sec @ 20GeV/c• High-resolution beam: Dp/p~0.1%

Open a new platform for hadron physics
Exp. Target (FF)Collimator
15kW Loss Target(SM)Dispersive Focal Point (DFP)
Dp/p~0.1%
11Charmed Baryon Spectroscopy
Using Missing Mass Techniques
Inclusive p(p-,D*-) Yc*+(Target)

Yc*+p(p-,D*-p)D0-,D*-p)Y ’ )(p(pcp(p)D0(Yc’)

Conducted by the E50 experiment at J-PARC

12

Large Acceptance Spectrometer
2m
Internal TOF

Magnet2.1 TmRing Image
Cherenkov
Counter Decay p(p+)

Internal DCK+

LH2-target

20 GeV/c
Beam p-Beam GC

pFiber tracker

TOF wall
DC
Internal TOF

p s-Acceptance: ~ 60% for D*, ~80% for decay p+
Resolution: Dp/p~0.2% at ~5 GeV/c （Rigidity： ~2.1 Tm)
13

Schematic Level Structure of Heavy Baryons• λ and ρ motions split (Isotope Shift)• HQ spin multiplet （𝑠𝐻𝑄 ± 𝑗𝑟𝑒𝑠𝑡 ）q-q r
P-waveρ modeqqG.S.
mQ = mqλ modeq-q... ...

Q

q𝑠𝐻𝑄 ± 𝑗𝑟𝑒𝑠𝑡lQ
mQ > mq
14

CQM calculation (Lambda)
Strange baryons
800

L(1/2-,3/2-,5/2-)

S(3/2+)

Y* - YG.S. [MeV]

L(1/2-,3/2-)
L(1/2-,3/2-)

700

Charmed baryons

cs

Lc(1/2-,3/2-,5/2-)

rr

600

Lc(1/2-,3/2-)

500
400

l

Lc(1/2-,3/2-)

300

Sc(3/2+)200

Sc(1/2+)100

S(1/2+)
L(1/2+)

00 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Lc(1/2+)

MQ [MeV/c2]
non-rel. QM:H=H0 +Vconf +VSS+VLS+VT
r-l mixing (cal. By T. Yoshida)

15

CQM calculation (Sigma)
Strange baryons
800

S(1/2-,3/2-,5/2-)
S(1/2-,3/2-)

S(3/2+)

Y* - YG.S. [MeV]

S(1/2-,3/2-)

700
600
500

Charmed baryons

csrll

Sc(1/2-,3/2-)
Sc(1/2-,3/2-,5/2-)
S (1/2-,3/2-)
c400
300

Sc(3/2+)200

Sc(1/2+)100

S(1/2+)
L(1/2+)

00 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Lc(1/2+)

MQ [MeV/c2]
non-rel. QM:H=H0 +Vconf +VSS+VLS+VT
r-l mixing (cal. By T. Yoshida)

16

Level structure (Exp.)
900
Threshold
K*N(1830)

Sh(1740)
Lh(1663)

L

S

Lc

Sc

800
700

600
500

1830 5/21800 1/21690 3/21670 1/2-

S*p(1520) 400

1520 3/2-

KN(1432) 300

1405 1/2-

1775 5/21750 1/21690 ??
1670 1/21620 1/21580 3/2-

1383 3/2+

2800 ??

DN(2800)

2628 3/2-

S*p(2650)

2593 1/2-Sp(2590)

Sp(1330) 200

2519 3/2+
2455 1/2+1192 1/2+

1000

D*N(2950)

2940 ??
2880 5/2+?
2765 ??

Threshold1116 1/2+

2286 1/2+

 λ /r mode assignment is not established yet.
 Level structure of Yc is little known.

17Experimental Situation in Charm Baryons• Experimental information is limited.
– Many states in excited states have yet to beobserved.
– Spin/Party, (Isospin) still not determined• L(2880)/L(2940) and beyond– Orbital Angular momentum is still unclear.
– λ /r mode assignments are important.

18

Lc(2765)?
Lc(2880)

Lc(2880)->pSc(2455)

Lc(2880)Belle,PRL98, 262001(’07)
Lc(2940)

Sc(2455)(Lc(2880)->pSc(2455))

Lc(2880)->pD0
Lc(2940)->pD0(Lc(2880)->pSc(2520))
Sc(2520)Babar, PRL98, 012001(’07)

19Production Rate
S.H. Kim, A. Hosaka, H.C. Kim, HN, K. Shirotori, PTEP, 103D01, 2014.

p-p

D*qeff

D, D*Yc*

L C.S. DOES NOT go down at higher L when qeff >1 GeV/c
 λ modes are excited by a simple mechanism
20Missing Mass Spectrum (Sim.)• ~1000 Yc*/nb/100 days
HQS doublet• Sensitivity: s ~0.1 nb
for Yc* w/ G =100 MeV

HQS doublet?

1/2- 3/2L=1

5/2+3/2+
L=2

1/2+
L=0Lc(2625)

s ~1 nb
Lc

Lc(2880)

Lc(2595)

Lc(2940)
Sc

S c*

1:2

Sc(2800)

3:2

Production rate
• Note on HQ doublet states:– If they are LS partners, j>=L+1/2 and j<=L-1/2
Prod. Ratio of j> to j< = (L+1)/L– Spin(/Parity) of the HQ doublets can be
determined from the Prod. Rates (Spins/Parities ofY*c’s are not established experimentally…)– c.f. L(2880)=5/2+, as reported by Belle, will beable to examined with its LS partner if it is an L=2
l-mode state22

Charmed Baryon Spectroscopy
Using Missing Mass Techniques
Inclusive p(p-,D*-) Yc*+(Target)Yc*+p(p-,D*-p)D0-,D*-p)Y ’ )(p(pcp(p)D0(Yc’)

Conducted by the E50 experiment at J-PARC

23

Decay Properties
qqq

qq

qQ

qqQ

r mode (qq)l mode [qq]G(Scp ) > G(pD)

G(Scp ) < G(pD)24

Hint in R(NK)/R(pY)
L(1890)3/2+S(1775)1/2L(1690)3/2-L(1820)5/2+
S(1750)1/2-S(1670)3/2- L(1670)1/2L(1520)3/2-0r

0.5
R(NK)/(R(NK)+R(pY))

1PDG Data indicates ……
• Decay ratios in known hyperons
SUGGEST the l/r mode states• l/r mode ID by Prod. Rates
correlate w/ Decay Ratios→ to be establishedl* Phase space factor: p2L+1 corrected

More clearly identified in charmed baryons
25Decay Products
Lc(2940)->Sc0 p+Lc(2940)-> p D0with Lc+ p+ p- selected

NpSc ~ 200(BRpSc =13%)

Sc0- ~ 320
Sc++NppD
NpSc ~ 200D0(BRpD++=20%)
Sc

SUM
SignalMain BG* Decay products can be seen clearly owing to the large acceptance.
* Decay meas. strongly assists the missing mass spectroscopy.
• Branching ratios: Diquark corr. affects G(Lc*->pD)/G(Lc*->Scp).
• Angular distribution: Spin, Parity
26

Detector R&D are issues…
2m
Internal TOF

FM magnet

Ring Image
Cherenkov
Counter Decay p(p+)

Internal DCK+

LH2-target

20 GeV/c
Beam p-Beam GCpFiber tracker

TOF wallDC
Internal TOFp s-Acceptance: ~ 60% for D*, ~80% for decay p+
Resolution: Dp/p~0.2% at ~5 GeV/c （Rigidity： ~2.1 Tm)
27

High rate BFT at K1.8
K. Miwa et al., Tohoku U.

Beamline Fiber Tracker
Can operate stably under a highintensity beam.
Structure
320 ch of 1mm f fibers
Two staggered layers
MPPC readout
We designed the high density
MPPC PCB.

We have finished the design.
Detector and MPPC PCB are being
produced now.

To be Enlarged for E50

We will use 10 EASIROC test board tooperate 320 MPPCs, because wewant to install this detector as soonas possible.
28

RICH

PhotonDetector

T. Yamaga
HUA Master Thesis Award 2014

~5mMirror
AerogelParticle
Simulation

C4F10

Photon angle
AerogelConceptual Design: Done!
-> Test Experiment
29

RICH R&D is in progress

25.6 mmElectron
0.75 GeV/c

Measured RING IMAGE
by 8x8 MPPC Array

Spherical
Mirror
25.6 mm2014.11.30

8x8 MPPC
Photo Sensor Array

30

Summary• What can we learn from heavy baryons…
1. Quark-diquark structure of heavy baryons• Mass spectrum• Production Rate• Decay Branching ratio

2. Diquark is an essential degree of freedom?
• Information to access “wave function” in the con• Detector R&D are in Progress– High Rate Trackers– RICH PID counters– High Speed Electronics/DAQ
31

We welcome your join!
E50 collaboration:
Jung-Kun Ahn1, Shuhei Ajimura2, Kazuya Aoki3, Johann Goetz4, Ryotaro Honda5, Takatsugu Ishikawa6,
Yue Ma7, Koji Miwa8, Yoshiyuki Miyachi9, Yuhei Morino3, Takashi Nakano2, Megumi Naruki10,Hiroyuki Noumi2, Kyoichiro Osawa3, Fuminori Sakuma7, Takahiro Sawada11, Kotaro Shirotori2,Yorihito Sugaya2, Tomonori Takahashi2, Kiyoshi Tanida12, Wen-Chen Chang11, and Takumi Yamaga2
1 Physics Department, Korea University, Seoul 136-713, Korea
2 Research Center for Nuclear Physics (RCNP), Osaka University, Osaka 567-0047, Japan
3 Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research

Organization (KEK), Ibaraki 305-0801, Japan
4 Institute of Nuclear and Particle Physics, Ohio University, OH 45701, USA
5 Department of Physics, Osaka University, Osaka 560-0043, Japan
6 Research Center for Electron Photon Science (ELPH), Tohoku University, Miyagi 982-0826, Japan
7 RIKEN Nishina Center, RIKEN, Saitama 351-0198, Japan
8 Physics Department, Tohoku University, Miyagi 980-8578, Japan
9 Physics Department, Yamagata University, Yamagata 990-8560, Japan
10 Department of Physics, Kyoto University, Kyoto 606-8502, Japan
11 Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
12 Department of Physics, Seoul National University, Seoul 151-747, Korea
32