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1 High High Multiplicity Multiplicity Study Study E.Kokoulina, A.Kutov for SVD-2 Collaboration JINR, Russia & GSTU, Belarus ISMD 2007, LBNL Berkeley, August, 4-9

High Multiplicity Study

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High Multiplicity Study. E.Kokoulina, A.Kutov for SVD-2 Collaboration JINR, Russia & GSTU, Belarus. ISMD 2007, LBNL Berkeley, August, 4-9. OUTLINE. Introduction Gluon Dominance Model (e + e - , pp, pA, pp) “Thermalization” project status Outlook. _. - PowerPoint PPT Presentation

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Page 1: High Multiplicity Study

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High High Multiplicity Multiplicity

StudyStudyE.Kokoulina, A.Kutov for SVD-2 Collaboration JINR, Russia & GSTU, Belarus

ISMD 2007, LBNL Berkeley, August, 4-9

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OUTLOUTLINEINE IntroductionIntroduction

Gluon Dominance Model (eGluon Dominance Model (e++ee--, , pp, pA, pp)pp, pA, pp)

“ “Thermalization” project status Thermalization” project status

OutlookOutlook

ISMD 2007, LBNL Berkeley, August, 4-9

__

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IntroductiIntroductionon

We use the unified approach to the multiplicity description at HEP. It is based on essentials of QCD and on the main experimental phenomena in multiparticle dynamics.

We are interested the high multiplicity (HMHM) region: n > n(s).

_

ISMD 2007, LBNL Berkeley, August, 4-9

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- annihilation

ee

proton (nucleus) collisionsproton-antiproton- annihilation

pQCD & hadronizationSoft Photons

V. Kuvshinov, E.K. Acta Phys.Polon. B13 (1982).

IntroductiIntroductionon

THERMALIZATION project

ISMD 2007, LBNL Berkeley, August, 4-9

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ee

First stage (cascade): a) gluon fission; b) quark bremsstrahlung; c) quark pair creation.

hadronsgqqqZee ?),()( 0

Second stage (hadronization): BD

.)1(1PN

p

hpH

p zN

nQ

Convolution: of two stages.

!

)1)...(1(pk

p

p

m

p

pppm km

k

km

m

m

mkkkP

quark fission -> NBD

Gluon Dominance Model Gluon Dominance Model (GDM): e(GDM): e++ee-- annihilation annihilation

ISMD 2007, LBNL Berkeley, August, 4-9

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Pn in -annihilation at 22 (TASSO) and 161 GeV (OPAL) ; H(q) at 161 GeV.

ee

E. K. Minsk, NPCS (2002)]; ISMD32,2002.

22 GeV

Pn 161

GeV

Pn H(q)

161 GeV

GDM: eGDM: e++ee-- - annihilation - annihilation

ISMD 2007, LBNL Berkeley, August, 4-9

qq

nn nn

Page 7: High Multiplicity Study

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s s

hgn

)( hgg nN - maximal (average)

multiplicity of hadrons from one gluon while its passing through of hadronization is constant -> fragmentation mechanism of hadronization (one to one)

gluon hadronization is softer than quark one:

2.~/ qg NN

gN

GDM: eGDM: e++ee-- - annihilation - annihilation

ISMD 2007, LBNL Berkeley, August, 4-9

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After an inelastic collision of two protons the part of energy are converted into the thermal (the dissipating energy) and one or few gluons become freeGluons may give cascadeSome of gluons (not of all) leave Quark-Gluon System (QGS) – are evaporated and are converted to hadrons.

1st

stage

2nd

stage

GDM: pp - interactionsGDM: pp - interactions

ISMD 2007, LBNL Berkeley, August, 4-9

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Our model study had shown: quarks of initial protons are staying in leading particles (from 70 to 800 GeV/c). Multiparticle production (MP) is realized by gluons*). We name them active ones. _________________________________________*The dominance role of gluons at multiparticle production (MP) was proposed S.Pokorski and L. Van Hove (1975), P. Carruthers (1984).

GDM: pp - interactionsGDM: pp - interactions

ISMD 2007, LBNL Berkeley, August, 4-9

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1. Scheme with the branch of gluon in QGS (TSMB)

2. Scheme without the gluon branch (TSTM)

E.K. and V.Nikitin. 7th Int. school-seminar The actual problems of Microworld Physics, Gomel, Belarus. 1 (2004)

GDM: pp - interactionsGDM: pp - interactions

ISMD 2007, LBNL Berkeley, August, 4-9

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MD of active gluons at the moment of impact (Poisson)

MD of branch gluons (Furry) for the first scheme

MD at the hadronization stage (BD)

GDM: pp – interactions GDM: pp – interactions (scheme with branch) (scheme with branch)

ISMD 2007, LBNL Berkeley, August, 4-9

Page 12: High Multiplicity Study

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- ratio of evaporated gluons to all active ones;

gluon hadronization parameters on second stage;

)5.0(~Nn h ,

N ~40. This value is very likely to the number of partons in the glob of cold QGP, which leads to production of soft photon excess. P.Lichard & L.Van Hove. Phys.Let. B245 (1990) 605.

GDM: pp – interactions GDM: pp – interactions (scheme with branch)(scheme with branch)

ISMD 2007, LBNL Berkeley, August, 4-9

Page 13: High Multiplicity Study

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E.K. Acta Phys.Polon. B35(2004)295

pp –pp – interactions (scheme interactions (scheme without branch)without branch)

After evaporation gluons leave QGS and fragment to hadrons. MD is convolution Poisson and BD

69 GeV/c 800 GeV/c

chn chn

nPnP

ISMD 2007, LBNL Berkeley, August, 4-9

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p, GeV/c

Mg

N

69 2.48 +/-

0.20

6 4.24 +/-.13

1.63 +/-0.12

~2

102 2.75 +/

0.08

8 3.13 +/-.56

1.64 +/-0.04

2.2

205 2.82 +/- 0.20

8 4.50 +/-.10

2.02 +/-0.12

2.0

300 2.94 +/- 0.34

10 4.07 +/-.86

2.22 +/-0.23

9.8

405 2.70 +/-.30

9 4.60 +/-.24

2.66 +/-0.22

16.4

800 3.41 +/-2.55

10 20.3 +/-10.4

2.41 +/-1.69

10.8

m hn 2

pp –pp – interactions (without interactions (without branch)branch)

ISMD 2007, LBNL Berkeley, August, 4-9

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Hadronization Hadronization MechanismsMechanisms recombination mechanism

clan as independent intermediate gluon sourceqq

qqq

qq

Recombination:

1Meson

Baryon

Fragmentation:

1Meson

Baryon

B.Muller [nucl-th/0404015]

ISMD 2007, LBNL Berkeley, August, 4-9

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Mean multiplicity of π0 versus the number of nch

2

1

2

1

/)()(0

n

nn

n

nnnchtotnch

tot tot

tottotPnnPnn

pp – interactionspp – interactions (neutral)(neutral)

MD of π0 at 69 Gev/c Limits to max charged, neutral & total multiplicities (26, 16, 42).

gluon hadronization parameters for π0

Centaur (yes, HM region), AntiCentaur (no)

particle number limits

V. Grishin. Phys.El.Part.and At.Yad. 10 (1989)689.

)(0 chnn

ISMD 2007, LBNL Berkeley, August, 4-9

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62 GeV

E.K., Nikitin V. et al. ISHEPP2004.

.1!

1!

)(

)2(22

22

2

22

)2(2

2

1

11

2

2

2

2

22

1

1

1

1

11

nNmhnh

nNm

M

m

mm

nNmhnhnNm

M

m

mm

n

N

n

N

nC

m

me

N

n

N

nC

m

mesP

14.23.3 hn

)1( 21

.13/9/,8.1~/

,25.015.1,03.059.32

21

21

ndf

mm

1 2

pp – interactionspp – interactions (ISR, 30-60 GeV)(ISR, 30-60 GeV)Clan

(cluster) superposition consisting from one, two (or more) gluon fission

Soft ( ) & semi-hard ( ) components, and so on.

Pn

n

ISMD 2007, LBNL Berkeley, August, 4-9

1 2

Page 18: High Multiplicity Study

18

GDM h/ for pp: 70 GeV/c = 1.19+/-0.25 ,,, 800 GeV/c = 1.49+/-0.33 … 62 GeV ~ 1.6 ( ).

PHEN

IXh

hch

h

ch

n

n

nsmh

sn

sn

000 2

1

)(

1)/(

)(

2/)(

076.10 hn

pp(nucleus) – pp(nucleus) – interactions (h/interactions (h/ ratio) ratio)Au-Au 200 GeV/N, peripheral (60-92%).

GDM: PHENIX. Nucl.Phys.A757(2005).

the dominance of active gluon plenty in nucleus central collisions leads to the new kind matter formation –QGP

agreement with h/ ratio

pp

ISMD 2007, LBNL Berkeley, August, 4-9

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19

1.0)(,40,4 nTnmbmb inin

Soft photons Soft photons (SP excess)(SP excess)

Measured SP:

01.0,/1.0 xcGeVptσ(SP) are 5-8 times larger than expected ones from QED.

Assumption: QGS or excited new formed hadrons set in almost equilibrium state during a short period. That is why we use the black body emission spectrum:

.

1

8 3

3

T

h

ecd

dn

ISMD 2007, LBNL Berkeley, August, 4-9

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383

10112.4/)()(725.2,2

244.0)(

mVTnMVBKThc

kTVTn rr

3

3

3968

3

101010112.4/)()(,)()(

fm

T

TVTnT

T

TTnTn

rrr

)()(3 TLnTL L(fm)

L(fm)

10 11. 30 3.5

15 6.9 40 2.6

25 4.1 50 2.0

tp tp2 tppT

M.Volkov,E.K., E.Kuraev. Part. & Nucl. Let., 5 (2004)122

Soft photons Soft photons (SP excess)(SP excess) The number of SP is estimated by MVB

density ρ(T )=n(T)/V:

estimation of SP emission region

SP excess is the sign of hadronization

ISMD 2007, LBNL Berkeley, August, 4-9

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21

pp – annihilation pp – annihilation (experiment)(experiment)

__

J.Rushbrooke & B.Webber. Phys.Rep. C44(1978)1.)(sn

2f

)( 2GeVs

22 )1( nnnf

)(sn

n

)()( pppp nnn

32, 100 GeV/c

ISMD 2007, LBNL Berkeley, August, 4-9

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22

mNhm zNnzQzmQ )1(/1),1(),(

GDM: pp – GDM: pp – annihilation annihilation

.0/)(~ 22 Nnmf h

Experiments (10-100 GeV/c): a tendency to the production of leading mesons. f2 behavior explanation. The simple scheme with appearance at first moment of m active gluons. GF and f2 :

E.K. AIP. 828 (2006) 81

__

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GDM: pp – GDM: pp – annihilation annihilation

__

GDM includes intermediate quark topologies at the initial stage making only from valent quarks (“0”-, “2-”) or valent and vacuum ones (“4-”, “6-”). MD are superposition of them.

p

p

+ +0 00

0 + +

+ + + +…

(“0”)

(“2”)

(“4”)

ISMD 2007, LBNL Berkeley, August, 4-9

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,/ nnnP

.05.0:40:15:: 420 ccc

.5.1~/,61.074.1

,18.036.32 ndfn

mh

GDM: pp – GDM: pp – annihilationannihilation

__

14.75 GeV/c

mNhM

m

Gm

mNhM

m

Gm z

N

nPzcz

N

nPczQ )1(1)1(1)(

202

20

.)1(14

44

mNM

m

hGm z

N

nPzc

intermediate topology superposition

hadronization predominance at annihilation

Pn

ISMD 2007, LBNL Berkeley, August, 4-9

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Scientific programme: multiparticle dynamics study in p+p(A) interactions with HM (n>20) at IHEP U-70.

SVD-2 Collab.: Belarus, Czech Republic, Russia, Slovak Republic, Ukraine

project project “THERMALIZATIO“THERMALIZATION”N”

SVD-2 setup

V.V.Avdeichikov et al. JINR-P1-2004-190, Proposal ”THERMALIZATION”.

Micro strip VD, 10000 channels.

Drift tubes tracker, 2400 channels

Magnetic spectrometer

DeGa

Č

target

ISMD 2007, LBNL Berkeley, August, 4-9

10 10

mm

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Liquid hydrogen target

Trigger scintillation hodoscope (“camomile”) for the registration of rare events with HM:

20 elements: triangle h=18, thickness 1.8 mm

Project Project “THERMALIZATI“THERMALIZATIONON

ISMD 2007, LBNL Berkeley, August, 4-9

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project project “THERMALIZATIO“THERMALIZATION”N” Search for & new

collective phenomena study:

1. BEC of identical particles.

2. Ring events (Cerenkov gluon).

3. Soft photon cross section.

4. Grouping of secondary.

ISMD 2007, LBNL Berkeley, August, 4-9

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project project “THERMALIZATIO“THERMALIZATION”N”

1) M.I.Gorenstein & V.V.Begun, BITP, Ukraine [hep-ph/0611043]:at HM the experimental manifestation of BEC may be founded by the sharp increase of neutral meson multiplicity fluctuations at fixed total multiplicity.

ISMD 2007, LBNL Berkeley, August, 4-9

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project project “THERMALIZATIO“THERMALIZATION”N”2) RUN

2002: Ring event search [Seminar NPCS,Minsk,2006]. 4) RUN 2002: the indication to the grouping of secondary in the certain direction [Hep-ph/0612364]

Preliminary

Preliminary

ISMD 2007, LBNL Berkeley, August, 4-9

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project project “THERMALIZATIO“THERMALIZATION”N”

MD in pC, pSi and pPb

RUN 2002

pC

pSi pPb

ISMD 2007, LBNL Berkeley, August, 4-9

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project project “THERMALIZATIO“THERMALIZATION”N”Alignment taskAlignment task of detectors is an essential step

in the track reconstruction:

beforeafter

2006 data

ISMD 2007, LBNL Berkeley, August, 4-9

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project project “THERMALIZATIO“THERMALIZATION”N”

Z, mm

X, mm

Y, mm

ISMD 2007, LBNL Berkeley, August, 4-9

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““THERMALITHERMALIZATION”ZATION”

n=n=2222

ISMD 2007, LBNL Berkeley, August, 4-9

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““THERMALITHERMALIZATION”ZATION”

Multiplicity distributions for X and Y planes (n_beam<5)

Integrated MD for X, Y planes

Preliminary

Preliminary

ISMD 2007, LBNL Berkeley, August, 4-9

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• Data pA (Si,C, Pb) 2002 run will be study

• A set of pp data in 2007-2009 runs will be obtained.

• We expect interest phenomena in the HM region will be got.

OutlOutlookook

ISMD 2007, LBNL Berkeley, August, 4-9