1 Spectroscopy of Charmed Baryon Resonances at J-PARC H. Noumi, RCNP, Osaka University 1....

1

Spectroscopy of Charmed Baryon Resonances at J-PARC

H. Noumi, RCNP, Osaka University

1. Introduction2. High-p BL and CHARM Spectrometer3. Missing Mass Spectroscopy of baryons w/ heavy flavors

• production and decay• charmed and strange baryons

4. Summary

HADRON2015, Sep 15, 2015

How Hadrons are formed?

2

at LQCD

High E Low E

Quarks drastically change themselves below LQCD.

CurrentQuark

Hadrons are hardly described from current quarks

Composite Quasi-Particle

3

Low E

Effective DoF as building blocks of HadronsConfined in hadrons

High E

What we can learn from baryons with heavy flavors

4

• Quark motion of “qq” is singled out by a heavy Q • Diquark correlation

• Level structure, Production rate, Decay properties• sensitive to the internal quark(diquark) WFs.

• Properties are expected to depend on a Q mass.

q

q

q Q

qq

• λ and ρ motions split (Isotope Shift)• HQ spin multiplet （）

Schematic Level Structure of Heavy Baryons

5

λ mode

ρ mode

G.S.

P-wave

Ql

[qq]Q

r(qq)

mQ = mq mQ > mq

qq

q�⃑�𝐻𝑄± �⃑�𝐵𝑀

......

Spin-dep. Int.

ℏ𝜔𝜌

ℏ𝜔𝜆

=√ 3𝑚𝑄

2𝑚𝑞+𝑚𝑄

→√3(𝑚𝑄→∞)

Lambda Baryons (P-wave)

6

Sc(1/2+)

Sc*(3/2+)

Lc(2595, 1/2-)Lc(2625, 3/2-)

Lc o ｒ 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)

Sb(1/2+) Sb

*(3/2+)

Lb(5920, 3/2-)Lb(5912, 1/2-)

Lb(GS)

strange charm bottom

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

800

MQ [GeV/c2]

Y* -

YG.S

. [M

eV]

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 o ｒ 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

qq

l

r

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

800

MQ [GeV/c2]

Y* -

YG.S

. [M

eV]

Lambda Baryons (P-wave)

8

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 o ｒ 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

qq

l

r

?

9

High-res., High-momentum Beam Line

30 GeV proton beam

ProductionTarget

Pion BeamUp to 20 GeV/c

Spectrometer

T1

• High-intensity secondary Pion beam– 1.0 x 107 pions/sec @ 20GeV/c

• High-resolution beam: Dp/p~0.1%

K+

p-

ps-

decayp(p+)

2m

Dipole mag. RICH

ITOF

FiberTracker

DCDC

DCTOF

H2 TGT

0 5 10 15 201.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

1.0E+08

1.0E+09

[GeV/c]

Co

un

ts/s

ec

Prod. Angle = 0 deg. (Neg.)

Sanford-Wang 15 kW Loss on Pt Acceptance :1.5 msr%, 133.2 m

p-

K-

pbar

Charmed Particles

CHARM Spectrometer Design

10

D0(Yc’)

p(p)

Inclusive p(p-,D*-) Yc*+

p(p-,D*-p)D0

Yc*+

( p(p-,D*-p)Yc’ )

(Target)

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

K+

p-

ps-

decayp(p+)

20 GeV/c p-

2m

Dipole mag.

RICH

ITOF

FiberTracker

DCDC

DCTOF

H2 TGT

Cross Section: s (Lc) ~ 1 nb (no meas.) PTEP2014, 103D01(2014)

R&D works in progress.

Charmed Baryon SpectroscopyUsing Missing Mass Techniques

11

Production and Decay reflect [qq] correlation… l mode excitation to be favored in t-channel.

C.S. DOES NOT go down at higher L when qeff >1 GeV/c.

p

p-

D*-

Yc*+

L

D*, Dqeff

D0

p-p-

K+

𝐷0(𝑌 𝑐∗′

)

p (p)

PTEP2014, 103D01(2014)submitted to PRD

L = 1 L = 2L = 01/2+

LcLc(2595)

Sc(2800)Sc

Sc*

Lc(2625)

Lc(2880)

Lc(2940)

s ~1 nb

Missing Mass Spectrum (Sim.)• ~1000 Yc

*/nb/100 days• Sensitivity: s ~0.1 nb for Yc

* w/ G =100 MeV1/2- 3/2- 5/2+? 3/2+?

LS partner(HQS doublet)

LS partner?(HQS doublet?)

1 : 2

3 : 2

CS -> PTEP2014, 103D01(2014)

13

N

DYc*’

p

l mode r mode

Yc* Decay Pattern

Yc* Yc

*

Yc* Decays (sim.)

14

Lc(2940)->Sc0 p+

Sc++ p-

Sc0

Sc++

NpSc ~ 200 NpSc ~ 200

Lc(2940)-> p D0

NpD ~ 320 D0 SUM

Signal

Main BG

with Lc+ p+ p- selected

(BRpSc =13%) (BRpD =20%)

* Branching ratios: Diquark corr. affects (G Lc*->pD)/ (G Lc*->Scp).

• λ and ρ mode excitations interchangesqsQQ (+SO)

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

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

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

X*(3/2+)

X(1/2+)

Level Structure of double-Q baryons

qq

qλ mode

ρ mode

G.S.

P-wave

15

ql

QQ

r Q-Q

q

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

MQ [GeV/c2]

* -

[]

XX

GS

MeV

Xi Baryons

16

s c

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

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

Xcc(3/2+)

Xcc(GS, 1/2+)

X(1950, >=5/2?)

X(GS, 1/2+)

X*(1530, 3/2+)

X(1690, ??)

X(1820, 3/2-)

X(2030, ??)

KS

l

lr

Double Strange Double charm

non-rel. QM:H=H0 +Vconf +VSS+VLS+VT

-r l mixing (cal. By T. Yoshida)

Q

q

Ql

r

s c

Double Strange Baryon SpectroscopyUsing Missing Mass Techniques

17

Production and Decay reflect [QQ] correlation… u-channel production plays a role…

r mode excitation may be favored

p

K-

Xss*0L

Y*, Y

K*0 p-

K+

𝑌 𝑠∗′

(X𝑠𝑠∗ ′

)

K-(p)

JP rating

Width [MeV]

→Xp [%]

→LK [%]

→SK [%]

X(2500) ?? 1* 150?X(2370) ?? 2* 80? WK~9±4X(2250) ?? 2* 47+-27?X(2120) ?? 1* 25?X(2030) >=5/2? 3* 20+15

-5 small ~20 ~80

X(1950) ?? 3* 60+-20 seen seenX(1820) 3/2- 3* 24+15

-10 small Large Small

X(1690) ?? 3* <30 seen seen seenX(1620) ?? 1* 20~40?X(1530) 3/2+ 4* 19 100

18

LK(1610)

SK(1685)

Xp(1450)

Threshold

*LK (1908)*SK (1983)

*S K(1878)

*X p(1665)

WK(2166)

Little is known for X

• Narrow width: ~ a few 10 MeV• Decay mode: dominant?

Summary1. A general purpose spectrometer at the J-PARC High-p BL

– CHARM spectrometer will open a new platform to study hadron physics.

2. Quark-diquark structure of heavy baryons– Mass spectrum, Production Rate, and Decay Branching ratio– Information to access “wave function” of quark/diquark in

baryons

3. Systematic studies with different flavors are important to understand the internal quark-quark correlation in baryons further.

– Charmed, Strange, and Double Strange Baryons.

19

Backup slide

20

Collaboration

21

E50 collaboration:Jung-Kun Ahn1, Shuhei Ajimura2, Kazuya Aoki3, Johann Goetz4, Ryotaro Honda5, Takatsugu Ishikawa6, Chih-hsun Lin11, Yue Ma7, Koji Miwa8, Yoshiyuki Miyachi9, Yuhei Morino3, Ryotaro Muto3, Takashi Nakano2, Megumi Naruki10, Hiroyuki Noumi2, Kyoichiro Ozawa3, Fuminori Sakuma7, Shiin’ya Sawada3, 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, Japan11 Institute of Physics, Academia Sinica, Taipei 11529, Taiwan12 Department of Physics, Seoul National University, Seoul 151-747, Korea

22

JFY2015 JFY2015 JFY2016 JFY2017 JFY2018 JFY2019 JFY2020 ～

User Based Research

User Based Research

Next Term Plan at RCNP

CHARM for User Based

Research

Start up LEPS2 Exp

　　 Start Collaboration ＠ J-PARC

High performance Ge Detector

PID Detectors for CHARM

CHARM SpectrometerCommissioning

Startup CHARM Exp.

2ndary Beam Diagnostic Device

CAGRA Exp.

　　　　　　　　　　　　　　　　　　　 LEPS2 for User Based Research

Start Exotic Hadron spectroscopy

3D-muon detection system

Start upStart up Exp. by means of Muon Spin Rotation

Exp with BGOegg (Tohoku/ELPH)

LE

PS

Fa

cility

Commisioning LEPS2 Main Spectrometer

Radactive Beam Line

Start up Exp. of Hyper-deformed nuclei

R&D for High Speed Elesctronic/DAQ system

Spectroscopy of Exotic/Charm Hadrons

Spectroscopy of Hyper-deformed Nuclei

Fundamental/Application Science w/ DC Muon

Su

b-ato

mic S

cience R

esearch C

enter

MuSICCommissioning

Cy

clo

tron

Fa

cility

Intense Surface Muon Beam

Ultra-High time res.Muon Spin Rotation Meas.

High Res. Beam Linei

High Res. PID detectors for LEPS2

Position Sensitive g-ray detectors

Coincidence Algorism

Start upResearch for

Superdeformed Nuclei

R&D for g-ray Tracking Algorism

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

800

MQ [GeV/c2]

Y* -

YG.S

. [M

eV]

Lambda Baryons (P-wave)

23

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 o ｒ 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

qq

l

r

Designed Spectrometer

24

Large acceptance ~ 60% (for D*), ~85% (for decay p+) Good resolution: Dp/p~0.2% at ~5 GeV/c

20 GeV/cBeam p-

D0(Yc’)

p(p)

Inclusive p(p-,D*-) Yc*+

p(p-,D*-p)D0

Yc*+

( p(p-,D*-p)Yc’ ) (Target)

R&D for Key Devices

• Particle Identification (RCNP/Kyoto/Tohoku/RIKEN…)

– Ring Image Cherenkov Detector (RICH)• High rate tracker (Tohoku/Osaka/RCNP…)

– Scintillating Fiber Tracker (SFT)– Developed in experiments at K1.8

• High-speed DAQ system (RCNP/Osaka/Taiwan/KEK…)

– PC cluster-based DAQ scheme• Flexible “trigger”: not only (p-,D*) but also (K-,K*),…

– Grand designing is in progress

25

RICH: Design

26

• High-momentum PID– Mom. range: 2-16 GeV/c

⇒ Hybrid RICH– Aerogel + C4F10 gas– MPPC detector plane– Spherical mirror

Reconstructed Cherenkov angle

• Design Performances– Efficiency: ~99%– Wrong PID: 0.10~0.14%

⇒ Background level×1.05

RICH: Test Exp. at Tohoku/ELPH

27

Mirror

Measured Cherenkov angle

Ring Image

s q ~ 3.1 mrad < 4 mrad (requirement)

24 mm

e-Beam + Air 1.5m

Fiber Tracker

28

＊ J-PARC beam: time structure ⇒ Narrower time gate is more essential

to suppress accidental hits.– E50: 60 M/spill (30 MHz)

• Requirements– 1 MHz/1 mm fiber– Tracking efficiency: ~99%– Thin material thickness

• Focal plane & Beam tracking• Target downstream tracking

– Detector design– Simulation study– Readout electronics development

50 ns

Scintillating fiber tracker

DC 1.5-mm DL

E10: 12 M/spill (6 MHz) beam

High-speed DAQ system

29

Rate[event/spill]

Data [GB/spill]

Beam 60 M

Reaction H2 TGT (4 g/cm2) 3.63 M 50

Filtering Condition (On-line Data Reduction)C1 (1.1-2) M 15-28

C2 160 k 2.2

C3 DC and FT] (15-23) k 0.2-0.32

Total # of Channels: ~30,000• Tracker >17,100 ch• RICH: 10,000 ch• Hi-Res Timing/TOT: ~500 ch

• Event Rate and Data Reduction

High-speed DAQ system

30

Frontend modules

＊ Signal digitalization­ Pipelined system

Buffer PCs

＊ Data accumulation­ Several 10 GB memories

Filter PCs

＊ Event reconstruction­ 100-200 CPUs

Storage­ Local storage­ Transferred to

KEKCC/RCNP

＊ High-speed data link

　 (Local)

~50 GB/spill

<0.5 GB/spill

Streaming DAQ(~50 GB/spill)

31

LoI submitted by M. Naruki and K. Shirotori

X Baryon Spectroscopy w/ the High-p Secondary Beam

• Sizable yields are expected for a month.

• Past exp.

5 GeV/c

5 GeV/c

150 mb

5 mb

Inclusive X prod. in pp

Inclusive X prod. in K-p

C.M. Jenkins et al., PRL51, 951(1983) →

p(K-,K+) spectra

• Is the N* with a hidden c-cbar?• can be excited on its mass with 10 GeV/c pion

beam at J-PARC.• Its decay modes to .• Its family?

32

𝑌 𝑐

𝐷

𝑁

𝜋𝑷 𝒄

Lc(2880)

Lc(2940)

Sc*(2520)

Sc(2455)

Lc(2880)Belle, PRL98, 262001(’07)

Lc(2880)->pSc(2455)

Lc(2765)?

J=5/2 → J’=1/2

Lp=3 transition

JP=5/2+ for Lc(2880)

Lp=1 contribution may affect…

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

*(2520))

Is it a D-wave Lambda-c Baryon?If so, where is a spin partner ?

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

800

MQ [GeV/c2]

Y* -

YG.S

. [M

eV]

Lambda Baryons (P-wave)

34

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 o ｒ 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

qq

l

r

KN

Strange Baryon SpectroscopyUsing Missing Mass Techniques

35

Production and Decay reflect [qq] correlation…

p

p-

K*0

Ys*0

L

K*, Kqeff

p-

K+

𝑝 (𝑌 𝑠∗′

)

K- (p)

L(1405)

36

S(1

385)

S(1

385)

L(14

05)

(a)(p-,K*0) w/ pS decayL(

1520

)(b)(p+,K*+) w/ pS decay

S(1

775)

S(1

775)

Production rate tells how L(1405)/L(1520) deviates from/follows the quark-diquark configuration.

I = 0, 1 I = 1 only

Quark counting rule in hadron reactions

37

0K (1405)p

1-100 pb

J-PARC

𝑑𝜎𝑑Ω

1/ 𝑠𝑛−2H. Kawamura, et al., PRD 88, 034010 (2013)

Taken from T. Sekihara’s Slide

High-speed DAQ system

38

Common features– TDC base data taking– Pipelined data transfer with a high-speed data link.

• MPPC readout– Upgraded EASIROC: CITIROC/PETIROC chips

⇒ Open-It project with KEK electronics group

• Wire chamber readout– ASD + TDC readout modules

• High resolution TDC module– TDC + discrete amp– TDC LSB: ~25 ps

＊ Module R&D needs resources. However, those modules can be standard modules for the hadron hall experiments and so on.

High-speed DAQ system

39

Conventional trigger– Hardware trigger– Specific modules

⇒ Special trigger system

• Difficulties and disadvantages– No flexibility for byproducts – Module developing needs

cost and resources– Only available for E50

Planned E50 trigger­ On-line event reconstruction­ PC clusters

⇒ Flexible trigger system

• Advantages­ Flexibility for byproducts­ Cost of PCs having many

CPUs are low.

• Disadvantage­ Members have no experience.

Decay Properties

40

qq

qqQ

qqq

Qq

r mode (qq) l mode [qq] (G Sc p ) > (G pD)

(G Sc p ) < (G pD)

Strategy

1. Charmed baryon spectroscopy.Key issue is the p(p-,D*-)Lc cross section…

“C.S. ~ 1 nb” can be confirmed in ~10 days or so.– Go to the 2nd step when the C.S. << 1 nb.

2. Hyperon spectroscopy via (p-,K*0)… – Diquark motions ( /l r mode ID) for known states

Production Rate: favor l-mode ↔ r-mode through /l r mixing Decay Branching Ratio: G(NK)/G(pY) in terms of /l r modes

– x1000~10000 higher statistics

41

42

Populated states via p(p-,K*0)XL state Rate

(Rel.)

0L1/2+(1116) 1000 S1/2+(1192) 49S3/2+(1385) 244

1

lL1/2-(1405) 72L3/2-(1520) 127

r

L1/2-(1670) 7S3/2-(1690) 4L3/2- (1690) 13

l

S1/2- (1750) 4S5/2- (1775) 18

2L3/2+(1890) 25L5/2+(1820) 52

Cal. w/ t-channel K* ex. reaction at pp = 5 GeV/c

• l mode stateswell populated

• r mode statesexcited through / l r mixing (Pmix)

Pmix(strange) is given,

Pmix(charm) could be deduced.

Pmix(strange) > Pmix(charm)

S.H. Kim, A. Hosaka, H.C. Kim, HN, K. Shirotori, arXiv:submit/0978210, 14 May, 2014.

43

Hyperon production via p(p-,K*0)X• K- p decay

– K- tagged, Missing “p” gated

• p+Σ- decay– p+ tagged, Missing “Σ” gated

Inclusive

K- p decay

p+ S- decay

Green: BG

4x1011 pions (3 days)

p

S

BG

BG

44

Hyperon production via p(p-,K*0)X• K- p decay

– K- tagged, Missing “p” gated

• p+Σ- decay– p+ tagged, Missing “Σ” gated

Inclusive

K- p decay

p+ S- decay

Green: BG

4x1011 pions (3 days)

S

BG

BG

p

45

Hyperon production via p(p-,K*0)X• K- p decay

– K- tagged, Missing “p” gated

• p+Σ- decay– p+ tagged, Missing “Σ” gated

Inclusive

K- p decay

p+ S- decayS

BG

BG

HQ Doublet

5/2+ 3/2+

3 : 2

L = 2p

Hyperon Production (Fitting Results)• Extract 7 states.

– Constraint from known M & G

– BG: 5th O. Polynomial F.

• Cross Section– / l r mode ID– / l r mixing: Pmix(strange)

(r-mode C.S.)– HQ spin multiplets

• G (KN)/ G (pY)– / l r mode ID

Inclusive

K- p decay

p+ S- decay

L(1890)(3/2+)L(1820)(5/2+)

S(1775)(5/2-)S(1750)(1/2-)

L(1670)(1/2-)

L(1690)(3/2-)

S(1670)(??)

Decay mode: G (NK)/ G (pS)

47

• Hyperon data indicate mode dependence → Errors should be improved.• No data in charmed baryons

0 0.5 1

KN/(KN+pS)

L(1890)3/2+L(1820)5/2+

S(1750)1/2-

S(1670)3/2- L(1670)1/2-

L(1690)3/2-

S(1775)1/2-

L(1520)3/2-

PDG Data

lr

• l/r mode ID by productions correlate w/ Decay Ratios → to be established• The ratios <-> Pmix(strange)

lr

Decay mode: G (NK)/ G (pS)

48

• Hyperon data indicate mode dependence → Errors should be improved.• No data in charmed baryons

0 0.5 1

KN/(KN+pS)

L(1890)3/2+L(1820)5/2+

S(1750)1/2-

S(1670)3/2- L(1670)1/2-

L(1690)3/2-

S(1775)1/2-

L(1520)3/2-

0 0.5 1

KN/(KN+pS)

L(1890)3/2+L(1820)5/2+

S(1750)1/2-

S(1670)3/2- L(1670)1/2-

L(1690)3/2-

S(1775)1/2-

L(1520)3/2-

PDG Data Expected

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

800

MQ [MeV/c2]

Y* -

YG.S

. [M

eV]

Baryon spectroscopy in different flavors

49

s c

non-rel. QM:H=H0 +Vconf +VSS+VLS+VT

-r l mixing (cal. By T. Yoshida)

Sc(1/2+)

Lc(1/2+)

Sc(3/2+)

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

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

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

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

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

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

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

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

S(1/2+)

L(1/2+)

S(3/2+)

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

ll

r rr

Strange baryons Charmed baryons

Peak fitting for p(p+,K*+)S*+

50

(p+,K*+) w/ KN decay

S(1670)(??)

S(1775)(5/2-)S(1750)(1/2-)

M and G of 3 S*+’s are fixed first.

Expected Yield• Conditions

– s(p(p-,K*0)L)= 53 mb, others: cal. by t-ch. K* ex. model– t-channel dominance: ~exp{2.5(t-t0)}– 10 MeV mass resolution, DW(K*0) ~ 70% – BG source: JAM at pp=5 GeV/c

• Yield for 1013 pions ( 100 days w/ 7 Mpps)– 4 g/cm2 H2 TGT

– Large production yield: ~6 M/1mb (w/ εana~0.5)– Large decay events: DW(pS/KN) ~ 70%

• 210 k for L* -> K-p, 140 k for L* -> p-S+ if br(10%)51

52

High-res., High-momentum Beam Line• High-intensity secondary Pion beam

• High-resolution beam: Dp/p~0.1%

Dispersive Focal Point (DFP)Dp/p~0.1%

Collimator

15kW Loss Target(SM)

Exp. Target (FF)

Pion BeamUp to 20 GeV/c

53

High-res., High-momentum Beam Line• High-intensity secondary Pion beam

• High-resolution beam: Dp/p~0.1%

D D DDQDQQ QQ QQ QQ (QQQQ)DD

S S S

Collimator for Beam Re-define

Dispersive Focal PlaneFor Mom. Meas.

ProductionTarget

Exp. Target

Spectrometercollection Dispersion

Basic performances• Resolution

­ Missing mass resolution○ Lc

+: 16.0 MeV

○ Lc(2880)+: 9.0 MeV

• Acceptance­ for D*- (K+p-p-): 50-60%­ for decay particles: ~85%

＊ complete coverage cos q > -0.5

exp(bt)

Isotropic in CM

Acceptance: D*- detection

Lc(2940)+ → Sc(2455)0 + p+

Forward direction(Beam direction)

54

Backup slides for estimation of the production Cross Section

55

56

Calculated production rates (revised)pp=20 GeV/c

Mass(GeV/c)

“ud” isospin factor

Yc*

Spin factorqeff

(GeV/c)Rate

(Relative)

Lc1/2+ 2286 1/2 1 1.33 1

Sc1/2+ 2455 1/6 1/9 1.43 0.03

Sc3/2+ 2520 1/6 8/9 1.44 0.17

Lc1/2- 2595 1/2 1/3 1.37 0.93

Lc3/2- 2625 1/2 2/3 1.38 1.75

Sc1/2- 2750 1/6 1/27 1.49 0.02

Sc3/2- 2820 1/6 2/27 1.50 0.04

Sc1/2- ’ 2750 1/6 2/27 1.49 0.05

Sc3/2- ’ 2820 1/6 56/135 1.50 0.21

Sc5/2- ’ 2820 1/6 2/5 1.50 0.21

Lc3/2+ 2940 1/2 2/5 1.42 0.49

Lc5/2+ 2880 1/2 3/5 1.41 0.86

L=0

L=1

L=2

57

Populated states: (p-,K*0)pp=4.5 GeV/c

Mass(GeV/c)

isospin factor

Spin factor

qeff

(GeV/c)Rate

(Relative)(s mb)

L1/2+ 1116 1/2 1 0.29 1 53(+-2)*S1/2+ 1192 1/6 1/9 0.32 0.049 2.6S3/2+ 1385 1/6 8/9 0.38 0.244 12.9

lL1/2- 1405 1/2 1/3 0.36 0.072 3.8L3/2- 1520 1/2 2/3 0.40 0.127 6.7

r

L1/2- 1670 0.007 0.4S3/2- 1690 0.004 0.2L3/2- ’ 1690 0.013 0.7

l

S1/2- ’ 1750 1/6 2/27 0.53 0.004 0.2S5/2- ’ 1775 1/6 2/5 0.55 0.018 1.0L3/2+ 1890 1/2 2/5 0.56 0.025 1.3L5/2+ 1820 1/2 3/5 0.52 0.052 2.8

L=0

L=1

L=2

excited through l/r mixing

58

Production Rate

• t-channel D* Reggeon at a forward angle

and depend on:

1. Spin/Isospin Config. of Yc

2. Momentum transfer (qeff)

Production Rates are determined by the overlap of WFs

)2(exp)(~ 22 A/-q/AqI effL

effL

A~0.42 GeV ([Baryon size]-1)qeff~1.4 GeV/c

Spin/Isospin Factor

iefff rqiR )exp(2 ~

D* (q: mom. transfer)

p- D*-

p Yc+

L“ud” “ud”

u c

A. Hosaka et al.,paper in preparation.

59

Production Cross SectionA. Hosaka et al., paper in preparation.

1 101E-05

1E-04

1E-03

1E-02

1E-01

1E+00

1E+01

1E+02

1E+03

s/s0

s (m

b/sr

) p(p-,K*)L

pp=20 GeV/c

p(p-,D*)Lc<7nbat BNL

exp.

10 nb

0.1 nb

• Experimental data:– s (p(p--,D*-)Lc) < 7 nb (68%CL) (BNL exp., 1985)– BG spectrum is well reproduced by a MC simulation w/ JAM

• Regge Theory suggests 10-4 of the hyperon production– s (p(p--,D*-)Lc) ~ a few nb

Regge Theory

J.H. Christensen et al., PRL55, 154(1985)

+ JAM- Data

D*

Comment on the Coupling Constant

• Comparison of gD*D*p/gK*K*p and gLcND/gLNK*

– Estimated by means of the Light Cone QCD Sum Rule

– Exp. Data

• Taking gD*D*p/gK*K*p~1, gLcND*/gLNK*~0.67

　　　　　→　 We still expect s (p(p-,D*)Lc) ~a few nb.

gK*K*p gD*D*p gD*D*p/gK*K*p

3.5* 4.5 1.3

gK*Kp gD*Dp gD*Dp/gK*Kp

4.5* 7.5 1.7

A. Khodjamirian et al.EJPA48, 31(2012)

gLNK* gLcND* gLcND*/gLNK*

-6.1+2.1-2.0 -5.8+2.1

-2.5 0.95+0.35-0.28

gLNK gLcND gLcND/gLNK

7.3+2.6-2.8 10.7+5.3

-4.3 1.47+0.58-0.44

gK*Kp gD*Dp gD*Dp/gK*Kp

~4.5 8.95+-0.15+-0.9 ~2+-0.2

M.E. Bracco et al.Prog. Part Nucl. Phys. 67, 1019(2012)

*note:g[Bracco]/2=g[Khodjamirian]

60

Comparison in strange sector

1 10 1000.1

1

10

100

1000pi-p->K0Lambdapi-p->K0Sigma0pi-p -> K*0Lambdapi-p->K*0Sigma0pi-p -> K0Lambda(1405)pi-p -> K0Lambda(1520)pi-p->fnSeries23

s/s0

s(m

b)

s s∝ -a

61

Backup slides for the BG studies

62

Considered BG for BG reduction

63

1. Main background– Strangeness production including the (K+, p-, ps

-) final state

2. Wrong particle identification– Dominant cases: (p+, p-, ps

-), (p, p-, ps-)

• PID miss-identification of p/p as K+: ~3%• Productions of and p are ~10 times higher than K.

– Contribution of other combinations are negligible.• (K+, K-, s

-), (K+, -, Ks-), ( +, K-, s

-), (p, K-, s-), …

– Semi-leptonic decay channels: (K+, m-, ps-) (K+, e-, ps

-) • D0 mass cannot be reconstructed.

3. Associated charm production: Including D*-

– D** production: D**0, -→D*- + p+,0

– D0,+ + D*-, D*0,+ + D*- pair production– Hidden charm meson (J/y, y, cc) production: Decay to D*-

JAM (PRC61 (2000) 024901 ）3.4 mb

26 mb

Very Small and No peak structure ： shoulder at ~2.45 GeV/c2

Main backgroundAll events including K+, p-, p-

＊ Less information from old experiments­ s Total of p- p @ 16 GeV/c : 25.7 mb 　⇔ Strangeness production: 3.4 mb

⇒ A few mb­More than 106 times

higher than Yc* signals (1 nb)

• Background source­ K*0(→K+, p-) + p-

­ KKbar (K*K*bar) production + p-

­ Y K+ + p-

­ Non-resonant multi-meson production

＊ No special channel contributes to background

• Background generation Y. Nara et.al. Phys. Rev. C61 (2000) 024901

­ JAM (Jet AA Microscopic transport model)○ Use K+ and p- distribution from p- p reaction at 20 GeV/c

• s = 2.4 mb for (K+, p-, p-)

○ ssbar production multiplicity: ~1 (2 K+event: ~3%)

p- p reaction@ 16 GeV/c

J. W. Waters et al, NPB17 (1970) 445

Strangeness production C.S.

64

String model for JAMString model region in JAM: 4 GeV <√s < 10 GeV (~6.2 GeV for 20 GeV/c)• String production by hadron-hadron collision

­ String(hadron) + String(hadron)→st(qqbar) + st(qqq) + st(qqbar) + …

• String collision­ Not considered: Hadronization at first Hadron-hadron collisions⇒­ Color flux between strings was not also considered.

Hadronization model: Lund model

• qqbar production rate: uubar: ddbar : ssbar: ccbar = 1 : 1 : 0.3 : 10-11

• Input of production rate not obeyed to the spin (3S1, 1S0) statistics­ r/(p+r) = 0.5, K*/(K+K*)=0.6, D*/(D+D*)=0.75

＊ Almost same as of PYTHIA

Difference from PYTHIA­ String collision: Used simplified input model­ Hadronization process: Input parameters of resonances are different.­ Hard process

⇒To be checked by experimental data

65

JAM simulation check

Old data by BNL & CERN:

Invariant mass: M(K+p-p-) & M(K+ p-) ­ p- + p →Yc* + D*- @ 13 GeV/c, 19 GeV/c

• Background shape: Reproduced• D*- mass region (±20 MeV) events (BNL: 13 GeV/c data)

­ Data: 230 ± 15 counts (stat.) ⇔ Simulation: 240 ± 50 counts (stat. + sys.)

⇒ Old data background reproduced with small ambiguity (20-30%)

D*- mass

DataJAM simulation

M(K+p-) [GeV/c2]

D0 mass

M(K+p-p-) [GeV/c2]

66

_

_

_

CERN19 GeV/c data

B. Ghidini et al.NPB 111, 189 (1976)

BNL13 GeV/c data

J.H. Christenson et al. PRL 55, 154 (1985)

JAM simulation check: M(K+ p-)CERN19 GeV/c data

B. Ghidini et al.NPB 111, 189 (1976)

DataJAM simulation

PYTHIA simulation

M(K+p-) [GeV/c2] M(K+p-) [GeV/c2]

D0 mass_

D0 mass_

Peak position normalized

67

Backup slides for the BG reduction

68

Background reduction• S/N improvement (reduction factor):

­ Mass resolution: 2x106

­ Decay angle cut: 2­ Production angle cut 4 (depends on ds/dt)

“True D0”mass

K+

p-“Fake D0”mass

K+

p-

Signal Background

K+ scattering angle in CM K+ scattering angle in CM

SignalSimulationw/ acceptance

JAMSimulationw/ acceptance

pK

pp

pK

pp

Reduction = 3.8

Acceptance = 0.58

69

Background reductionTotal cross section @ 20 GeV/c: 25.1 mb

­ (K+, p-, p-) final state: 2.43 mb­ D0 mass region (1.852-1.878 GeV/c2): 21.7 mb (1/112)­ D*- tagging (Q = 4.3-7.5 MeV): 50.2 nb (1/434)

○ Old experiment: 1/100 by 4 time worse resolution

­ Acceptance: 1.2 nb (1/43)○ Detector: 50% for D* tagged background events

○ Momentum cut (pK+ & p -p > 2.0 GeV/c, Soft p- = 0.5-1.7 GeV/c)

• Total reduction: 112×434×43 ~ 2×106

S/N ratioBackground reduction• Total reduction: 112×434×43 ~ 2×106

• Event selection: 16

• Signal: 12 nb (1 nb×12 states) ­ B.R.×0.026 0.312 nb⇒­ Event selection×1/2 0.156 nb⇒

• BG: 2.43 mb ((K+, p-, p-) final state)­ 0.081 nb

⇒ S/N = 2.1 for D0 and D* mass region

S/N estimation• Signal: 12×1000 = 12000 counts• BG: 12000/2.1 = 5700 counts

⇒ Mass region: 2.2-3.4 GeV ⇒ ~5 counts/MeV

⇒ S/N = 1000/150 ~ 7­ 30 MeV region: 150 counts

• S/√N = 100/√1000 ~ 3 ­ Signal: s= 0.1 nb, G = 100 MeV: 100 counts⇒­ BG: 200 MeV region 1000 counts⇒

D0, D*- spectrum

• Full condition の 1/7 event, 12 nb in total: ~ 3200 events• Invariant mass を組むだけだと peak は見えない

­ BG が連続的な分布なので fitting すれば有意な peak と認識される

D0, D*- spectrum

• 1/7 event, 12 nb in total: ~ 3200 events• D0 cut で D*- の peak が確認できる

BG only

BG + SignalBG + Signal

BG only

73

D0, D*- spectrum

• Full condition の 1/7 event, 12 nb in total: ~ 2000 events• t-channel dominance を利用した event selection

­ Clear な peak が見える

Decay measurementSetup modification

Performances

75

Decay measurement

• Method: Mainly Forward scattering due Lorentz boost (q < 40°)­ Horizontal direction: Internal tracker and Surrounding TOF wall ­ Vertical direction: Internal tracker and Pole PAD TOF detector

• Mass resolution: ~ 10 MeV(rms)­ Only internal detector tracking at the target downstream

• PID requirement: TOF time difference ( p & K) ⇒ DT > 500 ps­ Decay particle has slow momentum: < 1.0 GeV/c

Internal tracker

Beam

Target

Surrounding TOF wall

Beam Target

Magnet pole

Pole PAD TOF wall

Magnet pole

76

Decay missing mass spectrum: SUM

＊Full event w/ background/ No “Lc+ p+ p- gated”

• Continuum background shape around Sc mass region

• Background events from Lc were the same as of (K+p-p-)

• Better S/N of p- tag. event than p+ tag.

Sc0 p+ Sc

++ p-

Lc+ p+ p- p D0

Sc0

Sc++

Lc+ D0

77

Study condition

• Assumed decay mode for Lc*+(JP = 3/2+, M = 2.94 GeV/c2)­ N + D: G = 0.4 ⇒ p D0: 0.2, n D+ :0.2­ Sc + p: G = 0.4 ⇒ Sc

++ p-: 0.4/3, Sc+ p0: 0.4/3, Sc

0 p+: 0.4/3○ Decay to Sc(2455) assumed

­ Lc + p + : p G = 0.2 ⇒ Lc+ p+ p-: 0.1, Lc

+ p0 p0: 0.1

• Yield estimation @ 1 nb case (~1900 counts)­ p D0: 0.2 1900×0.2×0.8 = ~300⇒­ Sc

++,0 p-,+: 0.4/3 1900×0.4/3×0.8 = ~200⇒○ Forward scattering of protons○ Wider scattering angle of pions○ Combined with 4-body D0 decay mode: 3 times larger yield

• D0→K+ p- (B.R.= 3.88%, acceptance = ~60%)

+ D0→ K+ p- p+ p- (B.R.= 8.07%, acceptance=~50%)• Background level of 4-body case is larger. But, it can be combined.

78

Comments• Decay measurement

­ Forward charged particle detection○ Particles scattered to q<40° due to Lorentz boost

­ Enough acceptance and angular coverage○ Pole PAD detector & internal TOF wall are used.

• Signal counts­ Combine 2-body and 4-body D0 decay channels

○ Sc p mode: > 500 counts

○ p D mode: > 800 counts

­ Braining ratio obtained with ~5% statistical error○ Assumed branching ratio @ 1 nb case & 100 days beam time

­ Angular distribution○ S, P, D-wave can be measured.○ Both polar and azimuthal angle can be measured.

• Other decay channels: Neutral channels­ p0 detection: Adding collimator­ n D+ mode: Downstream neutron counter

79

• λ and ρ motions split (Isotope Shift)• Spin-dependent Int. + Sij sisj

Λc(Pρ,cs) 1/2-, 3/2-, 5/2-

Sc(1/2+)

Λc(1/2+)

“Schematic” Level Structure of Heavy Baryons

λ mode

ρ mode

G.S.

P-wave

80

Ql

q-qQ

rq-q

Sc*(3/2+)

Λc(Pρ,cl) 1/2-, 3/2-

Sc(Pl,cs) 1/2-, 3/2-, 5/2-

Sc(Pl,cl) 1/2-, 3/2-

Sc(Pρ,cr) 1/2-, 3/2-

Λc(Pl,cl) 1/2-, 3/2-

mQ = mq mQ > mq

λ/ρ mode split(Isotope shift)

• λ and ρ motions split (Isotope Shift)• Spin-dependent Int.

“Schematic” Level Structure of Heavy Baryons

λ mode

ρ mode

G.S.

P-wave

81

Ql

q-qQ

rq-q

Λc(Pρ,cl)

Λc(Pρ,cs) Sc(Pl,cs)

Sc(Pl,cl)

Sc(Pρ,cr)

Λc(Pl,cl)

mQ = mq mQ > mq

λ/ρ mode split(Isotope shift)

+ Sij sisj

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

800

MQ [MeV/c2]

Y* -

YG.S

. [M

eV]

Baryon spectroscopy in different flavors

82

s c

non-rel. QM:H=H0 +Vconf +VSS+VLS+VT

-r l mixing (cal. By T. Yoshida)

Sc(1/2+)

Lc(1/2+)

Sc(3/2+)

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

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

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

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

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

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

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

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

S(1/2+)

L(1/2+)

S(3/2+)

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

ll

r rr

Strange baryons Charmed baryons

Level structure (Exp.)

83

1830 5/2-

1800 1/2-1690 3/2-1670 1/2-

1775 5/2-1750 1/2-1690 ??1670 1/2-

1580 3/2-1620 1/2-

1520 3/2-

1405 3/2-

1116 1/2+

1192 1/2+

1383 3/2+

SL ScLc

2286 1/2+

2455 1/2+

2519 3/2+2593 1/2-

2628 3/2-

2765 ??2880 5/2+?

2940 ??

2800 ??

0

100

200

300

400

500

600

700

800

900

Lh(1663)

Sh(1740)

KN(1432)

Sp(1330)

K*N(1830)

*S p(1520)

Threshold

DN(2800)

Sp(2590)

D*N(2950)

*S p(2650)

Threshold

JP rating

Width [MeV]

→NK [%]

→Lp [%]

→Sp [%]

S(1940) 3/2- 4* 220 <20 seen SeenS(1915) 5/2+ 3* 120 5-15 seen Seen

Λ(1890) 3/2+ 4* 95 20~35 3~10S(1880) 1/2+ 2* 220?S(1840) 3/2+ 1* 120?

Λ(1830) 5/2- 4* 95 3~10 35~75Λ(1820) 5/2+ 4* 80 55~65 8~14Λ(1810) 1/2+ 3* 150 20~50 10~40

Λ(1800) 1/2- 3* 300 25~40 SeenS(1775) 5/2- 4* 120 37~43 14-20 2-5Σ(1750) 1/2- 3* 90 10~40 　

seen<8 (Sh)15~55

Σ(1690) ?? 2*Λ(1690) 3/2- 4* 60 20~30 20~40

Σ(1670) 3/2- 4* 60 7~13 5~15 30-60Λ(1670) 1/2- 4* 35 20~30 25~55

Σ(1620) 1/2- 1*Σ(1580) 3/2- 1*

Λ(1520) 4* 19 45+-1 42+-1 84

KN(1432)

Lh(1710)

Sh(1790)

Sp(1330)

Threshold

K*N(1830)

*S p(1520)

Y* production and decay channels• Production

­ p- + p → L*, S*0 + K*0 (Ks0)

○ From K*0 → K+ p- reconstruction

­ p- + p → S*- + K*+ (K+)○ From K*+ → Ks

0 + p+ → p+ p- p+ reconstruction

＊ Both channels are needed to study each Y* resonance

• Decay­ KbarN mode

○ L* → K- p, K0bar n, (S*0 →K- p, K0

bar n)

○ S*- → K- n

­ pY mode○ L* → S- p+, S0 p0, S+ p- (S*0 → L p0, S- p+, S0 p0, S+ p- )○ S*-→ L p-, S- p0, S0 p-

＊ Detection of charged p or K

Simulation conditions• JAM simulation: p- + p reaction @ pp = 5 GeV/c (√s = 3.21 GeV)

­ w/ Charmed baryon spectrometer system

⇒ To check background­ K*0 → K+ p- reconstruction (B.R. = 0.67)­ K*+ → Ks

0 + p+ → p+ p- p+ reconstruction (B.R. = 0.67×0.5×0.69 = 0.23)

­ Production angle: Isotropic in CM

• Yield

＊ Np = 1.0×1012

­ 7 M/spill ×10 days­ 10 M/spill×7 days

⇒ NY* = 1.0 [mb] × 10-6 ×10-24×4.0 [g/cm2]×6.02×1023

×1.0×1012×0.5 (acceptance)×0.5 (efficiency)

= ~6.0×105 events (no branching ratio)

Acceptance

• Method: Mainly Forward scattering due Lorentz boost (q < 40°)­ Horizontal direction

○ Internal tracker and Surrounding TOF wall

­ Vertical direction○ Internal tracker and Pole PAD TOF detector

⇒ ~70% acceptance for K* detection

• Decay measurement: Angle in CM

⇒ Both pole and azimuthal angles: cosq > -0.5＊ Minor change of detector system needed

Beam Target

Magnet pole

Beam

Target

Internal tracker

Pole PAD TOF wallSurrounding TOF wall

Magnet pole

Signal responsesp(p-,K*0) ,L S0 and p(p-,K*+)S-

Peaking background

• Wrong combination of the K*0 background makes a fake peak.­ K*0 inv. mass background: K+ + slow p- from L→p p- event

• qK* selection enhanced peak structure

⇒ Only around 2.2 GeV/c region: All states have same structure.­ Peak with depends on width of the state.­ Continuum structure

• Contribution from higher K* resonance: Being checked

p- p -> L K*0

K*0 mass selectionp- p -> L K*0

K*0 mass selection+ qK* < 10°

Continuum structureup to a fake peak

Peaking background

• Wrong combination of the K*0 background makes a fake peak.­ K*0 inv. mass background: K+ + slow p- from L→p p- event

• qK* selection enhanced peak structure

⇒ Only around 2.2 GeV/c region: All states have same structure.­ Peak with depends on width of the state.­ Continuum structure

• Contribution from higher K* resonance: Being checked

p- p -> L(1690) K*0

K*0 mass selectionp- p -> L(1690) K*0

K*0 mass selection+ qK* < 10°

Continuum structureup to a fake peak

Invariant mass spectrum

• Signal: Only signals generated• Background: JAM simulation output result

Signal SignalSignal

K*0 KS0 K*+

Background BackgroundBackground

K*0 KS0 K*+

r

Decay missing mass: K*0 channel (L*)

• Signal: Only signals generated• Background: JAM simulation output result

Signal: K- p mode Signal: p- S+ modeSignal: p+ S- mode

p

BG: K- p mode BG: p- S+ modeBG: p+ S- mode

p

S-

S-

S+

S+

L

p

Summary• Large Acceptance• Peaking background

­ K+ (K0) + slow p: wrong combination makes a fake peak at ~2.2 GeV/c2

○ No affect < 2 GeV

­ Continuum BG above the Resonance mass○ No affect peak shapes

• Missing mass spectrum­ Major structure can be observed in the inclusive spectrum.­ /l r mode separation

○ Improve S/N in coincidence with a decay mode

­ Possible selection: Prod./Decay modes/Angular Dist.○ Decay Branching Ratios○ Production rate, density matrix

• Background Estimation­ Major structure can be observed at the signal level of 1 mb.­ BG shape seems a smooth function.

○ BG subtraction should be demonstrated.

Trigger

DAQ for charm experiment• Front-end

­ Fiber tracker: EASIROC­ DC: Belle2 CDC system­ SSD: APV25s1­ PMT1 (RICH): DRS4 or EASIROC­ PMT2 (Timing counter): DRS4

＊ LVDS signals are used for trigger.

• Trigger generation FPGA (UT3)⇒1. Trigger merger: Event tagging

○ Signal を 64 ns ごとに event tag をつけ UT3 に転送 (c.f. E16: Detector→merger （ LVDS ）、 merger→UT3 （光））

2. UT3: Trigger generation○ ここがいわゆる FPGA trigger を作る場所

3. Trigger distributer○ 各 distributer を clock 同期させ UT3 からの trigger 信号を module に送る

＊ Trigger 生成関連 module は E16 と共通­ Module 数は読みだす channel 数に依る (c.f. E16: 97156 ch)

• Trigger: Mass trigger­ Momentum analysis by DCs and fiber tracker

97

Trigger rate estimation for charmReaction rate: 3.63×106 /2.0 sec spill (LH2:4.0 g/cm2, 6.0×107 /spill)

­ Charged track rate: 3×106 /2.0 sec spill­ Average charged track multiplicity: 4

Momentum analysis in trigger level­ TOF >=2 & ITOF(negative) >=1 & SFT >=3 ­ Momentum analysis by DC & Fiber­ Charge information

⇒ Mass calculation from any positive and negative charge particles○ Mass assumed as positive = K+ and negative = p-

⇒ Mass > 1.50 GeV/c & p+ + p- > 11.0 GeV/c : 5-10 kHz○ 5% mass resolution (~4s from D0 mass)○ No accidental hits

DAQ system trigger rate capability: 20 kHz (90% efficiency)­ Less than 10 kHz needed for by-product trigger

Momentum analysis ­ Tracking: Trackers at the entrance and exit of the dipole magnet­ Transfer matrix: A few order of matrix needed­ Momentum resolution: 2-5% (Cell size position resolution)

98

Trigger Rate and Yield EstimationsReaction rate: 7.2×105 /2.0 sec spill (360 kHz)

­ LH2: 4.0 g/cm2, 10 M /spill

­ Charged track rate: 6.8×105 /2.0 sec spill (340 kHz)­ Average charged track multiplicity: 2.8 2(56%), 4(37%), 6(4.2%) ⇒

Momentum analysis in trigger level­ TOF or ITOF >= 2 & SFT >= 2­ Momentum analysis by DC & Fiber­ Charge information

⇒ Mass calculation from any positive and negative charge particles○K*0 : Mass assumed as positive = K+ and negative = p-

○KS0 : Mass assumed as positive = p+ and negative = p-

­ Trigger rate

＊K*0: 0.8 < Mass < 1.0 GeV/c2: 45 kHz @ 4 g/cm2, 10 M/spill

＊KS0: 0.44 < Mass < 0.55 GeV/c2: 31 kHz @ 4 g/cm2, 10 M/spill

­ DAQ system trigger rate capability: 20 kHz (90% efficiency)

＊Np = 1.0×1012

­ 7 M/spill ×10 days­ 10 M/spill×7 days

⇒ NY* = 1.0 [mb] × 10-6 ×10-24×4.0 [g/cm2]×6.02×1023 ×1.0×1012

×0.5 (acceptance)×0.5 (efficiency)

= ~6×105 events (no branching ratio)

How to check trigger system• Use known reaction: Hyperon production

­ p- p → L KS0 (~300 mb @ 4.5 GeV/c)

­ p- p → L K*0 (~130 mb @ 4.5 GeV/c) ­ (p- p → n r0)

＊ 100 mb ~1.0×10⇒ 4 events/h @ 1 g/cm2, 1 M/spill­ CH2 target is available for checking displaced vertex method.

• From L detection study w/ and w/o mass trigger­ Beam rate responses: Start from low beam intensity

○ Efficiency

­ Bias of trigger○ Momentum dependence: Detector position dependences○ Errors: Event slip

＊ Trigger system can be checked by various methods.­ With semi-online analysis­ Including momentum calibration and so on

100

Backup slides for Spectroscopy of QQq system

101

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

100

200

300

400

500

600

700

MQ [GeV/c2]

* -

[]

XX

GS

MeV

qQQ Baryon spectroscopy

102

s c

Xcc(1/2+)

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

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

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

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

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

X(1/2+)

X(3/2+)

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

l

lr

Double Strange Double charm

non-rel. QM:H=H0 +Vconf +VSS+VLS+VT

-r l mixing (cal. By T. Yoshida)

Structure and Decay Partial Width

103

qQ

qqQ

qQQ

r mode (QQ) l mode [QQ]

qq