Alice Workshop in Seoul

Hideyuki Obayashi

内容• 日程・場所• FCal の紹介• Di-baryon の検出可能性について• まとめ

• 日程

　　　 11/4　　広島空港　 9:40　　→　　仁川空港　11:20

　　　 11/7　　仁川空港　 19:20　　→　　広島空港　21:00

　　　　　　　　 (飛行機の遅れのため )

• 場所

　　　延世大学 (韓国 )

講演内容の紹介

FCAL (Forward CALorimeter)

PMDZ~360

FCAL

Forward Physics in ALICE

1.Physics at high gluon density - Color Glass Condensate

• Gluon distribution functions in proton and nuclei

2.Tests of pQCD predictions: pp• Forward particle production: 0 cross-section

3. Many interesting physics:• Jets, Jet quenching• Cronin effect, Shadowing• -tagging of the jets• Limiting Fragmentation• Diffractive physics• Centrality selection, Event plane determination• Exotic events …..

（以下、 Tapan Nayak さんのスライドより）

Gluon Distribution : Proton

Low-x gluon density is large and continues to increase as x0

It cannot grow forever

Fundamental question - Where does saturation set in ?

Deep inelastic scattering

LHC: extending the low-x ReachRHIC has opened the low-x frontier finding indications for new physics (CGC ?)

LHC will lower the x- frontier by another factor 30

Can reach x = 3 * 10-6 in pp, < 10-5 in PbPb

Photon measurements will remain unaffected by final state nuclear distributions and hence will measure true nuclear PDFs.

Hadronization through coalescence : c / D ratio

u d

d

u d

u

us

ds

c

c

d

u

d

u

us

ds

c

dudu

c

u d

c production through 3-body coalescence

c production through 2-body coalescence

c

c

c

cu

cu

D meson production through 2-body coalescence

D meson production through 2-body coalescence of diquark and c suppressed

c

Tcc/D > 0.34 x 10 -4 RHIC

> 0.8 x 10 -4 LHC

Hc/D > 0.8 x 10 -4

Hc/Ds > 0.25 x 10 -3

Kpp

ppK

c

c

)(

)( (udusuc)H 0c

Production ratios for predicted Multiquarks

c/D > 0.74 x 10 -4

c/Ds > 0.23 x 10 -3

c production at RHIC and LHC

Hc production at RHIC and LHC

Tcc production

まとめ• ALICE検出器の Up Grade について学んできた。

• 英語の勉強が必要だと感じた。

Buck up

aq

aq

aqbq

abc

rr

22

21

22121 2

1 r

1

3

4

2

1

Lattice calculation (Nakamura, Saito 05)

r r2

1

kiki

SSmm

C

3

1 kiki

SSmm

C

Phenomenological fit to hadron spectrum

quark-antiquark vs diquark

One gluon exchange

r

1

3

4

confining part

Spin part

u dd u

When does scalar diquarks survive

SHL, S. Yasui: EPJ C64, 283 (09)

Based on

3x CB = CM = 635 mu2

u d d ux 3 =

ji

jiji

BM ssmm

C

,

)(.confining.Kinetic Mass

Tetraquark : Tcc(S=1), Tbb(S=1), Tcb(S=1), Tcb(S=0)

cc

cc

Bcdcu

cq

Mdu

du

BTccg ss

mm

Cssss

mm

Css

mm

CCH 22

Previous works on Tcc

Z. Zouzou, B. Silverstre-Brac, C. Gilgnooux, J Richard (86), D. Janc, M. Rosina (04), Y. Cui, S. L. Zhu (07)

QCD sum rules: F Navarra, M.Nielsen, SHLee, PLB 649, 166 (2007)

simple diquark: SHL, S. Yasui, W.Liu, C Ko EPJ C54, 259 (2008), SHL, S. Yasui: EPJ C (09) in press

Tetraquark with two heavy antiquarks [ qq (cc)]

Tcc(S=1), Tbb(S=1), Tcb(S=1), Tcb(S=0) Stable configuration

du

c c

c

d

qc (qc) states vs qq (cc)

Di-bayron (Conf 1) – (qq) (qq) (qq)

u d

0+s d

H di-baryon marginal

s u

u d

s

u d

s

H di-baryon

CFL Phase of color superconductivity ?

2SC Phase

su

B

u

B

mm

C

m

C

4

32

4

32

22 4

3

4

3

u

B

u

B

m

C

m

C

Stability: competition between (us) (ds) diquarks and (ud) diquark

Di-baryon (Conf 2) – (qq) (qq) (qQ)

u d

0+ u s

Hc di-baryon Stable New prediction

u c

u d

u c

Hc di-baryon P c

cu

B

su

B

u

B

mm

C

mm

C

m

C

4

3

4

3

4

32

su

B

u

B

mm

C

m

C

4

3

4

32

Kpp

ppK

c

c

)(

)( (udusuc)H 0c

Stability: must be stable as (uc) has to break

u s

Mass diff M –MN M-M Mc-Mc Mb-Mb

Formula 290 MeV 77 MeV 154 MeV 180 MeV

Experiment 290 MeV 75 MeV 170 MeV 192 MeV

Mass diff M –M MK*-MK MD*-MD MB*-MB

Formula 635 MeV 381 MeV 127 MeV 41 MeV

Experiment 635 MeV 397 MeV 137 MeV 46 MeV

ji

jiji

B ssmm

C

,

.confining.Kinetic Mass

ji

jiji

M ssmm

C

,

.confining.Kinetic Mass

u d u d

s

s

du

B

mm

C

4

3conf.Kinetic Mass c

su

B

du

B

mm

C

mm

C

4

1conf.Kinetic Mass c

Example

• (Ex) PHENIX FoCAL

Detector assembly

“brick”

85 cm

17 cm6cm

6cm

Super tower

24

FCAL の案FCAL Design Parameters

Distance from the vertex ~ 370 cm (see note in previous page)

Eta Coverage 2.3 – 4.5

Radial Coverage 8cm to 73cm

Absorber Tungsten (W)

Depth 23-25 Rad. Length (~17cm)

Weight ~ 4Tons

SENSORS / READOUT:

Scintillator tiles APD readout

Silicon Pads / Pixels

参加者