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MULTIPARTICLE DYNAMICS STUDY by GLUON DOMINANCE MODEL. Kokoulina E ., Nikitin V. GSTU, Belarus & JINR,Dubna. The unified approach to multiplicity distribution (MD) description in high energy interactions:. - annihilation,. Proton (nucleus) collisions. Proton-antiproton- annihilation.

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slide1

MULTIPARTICLE DYNAMICS STUDY by GLUON DOMINANCE MODEL

Kokoulina E., Nikitin V.

GSTU, Belarus & JINR,Dubna

The unified approach to multiplicity distribution (MD) description in high energy interactions:

- annihilation,

Proton (nucleus) collisions

Proton-antiproton- annihilation

slide2

-

The region of high multiplicity (HM): n >> n(s) – mean muliplicity. Pn - multiplicity distribution (MD), Q(s,z) - generating function (GF) Q(s,z)= S Pn (s) z .

n

  • -annihilation - MD, moments… (the QCD Markov branching process + hadronization);
  • pp- interactions from 69 to 800 GeV/c by two schemes with and without gluon branch on 1st stage, modification of 2nd scheme by clan mechanism at higher energies;
  • -annihilation (~10-100 GeV/c).

Kuvshinov V. and Kokoulina E. Acta Phys.Polon.B13(1982) 533.

slide3

First stage (cascade):

a) gluon fission; b) quark bremsstrahlung; c) quark pair creation.

Second stage:

Hadronization. BD

K.Konishi et.al.NPB157(1979)45 A.Giovannini.NPB161(1979)429.

Convolution: of two stages

quark fission -> NBD

slide4

Pn

Pn

Pn

91.4GeV

50GeV

14GeV

Pn

H(q)

Pn

172GeV

189GeV

91.4GeV

Pn in -annihilation at 14, 50, 91.4, 172 and 189 GeV; H(q) at 91.4 GeV.

E. Kokoulina. Minsk, NPCS (2002)[hep-ph/0209334]; ISMD32,2002.

slide5

hadronizationgluon parameters ( ), 14 -189 GeV.

maximal (mean) multiplicity of hadrons are formed from gluon on the stage of hadronization.

hadronization of gluon are softer than quark.

slide6

Project“THERMALIZATION” (JINR , IHEP, SINP MSU, GGTU)

  • Experimental data pp (70 GeV).
  • Quark model. Yad.Fiz. 55 (1992) 820. Collisions of quark pair.
  • MC PHYTHIA code underestimates the s(nch) by two orders of magnitude at nch=18.

nch=18

The goal:

The study of MP at pp (pA) interactions in HM region: nch>20-30.

gluon dominance model gdm
Gluon Dominance model(GDM)
  • After an inelastic collision of two protons the part of energy are converted into the thermal and one or few gluons become free,
  • Gluons may give cascade – I stage;
  • Some of gluons (not of all) leave Quark-Gluon System (QGS) – are evaporated and are converted to hadrons – II stage.
slide8

Our model investigations had shown :quarks of initial protons are staying in leading particles (from 70 to 800 GeV/c).Multiparticle production (MP) is realizedby gluons. We name them active.

P.Carruthers about a passive role quarks:“…labels and sources of colour perturbation in the vacuum: meanwhile the gluons dominates in collisions and multiparticle production.”(1984)

The domination of gluons was first proposed by S.Pokorski and L.Van Hove (1975).

the multiplicity distributions md analysis are used to study mp processes
The Multiplicity Distributions (MD) analysis are used to study MP-processes.

Model with the gluon branch in QGS – branch model (TSMB)

or

Model without the gluon branch –

Thermodynamic model (TSMT)

E.Kokoulina, V.Nikitin. 7th Int. school-seminar The actual problems of Microworld Physics, Gomel, Belarus

V.1 (2004) [hep-ph/0308139]

tsmb convolution gluon and hadron md
TSMB –convolution gluon and hadronMD
  • MD for active gluons at the moment of impact – Poisson
  • MD for branch of gluons – Farry
  • MD for hadronization stage – Binomial (BD)
slide11

Scheme with branch:

- ratio of evaporated gluons to all active ones

, N – parameters of hadronization for gluon

Some of active gluons (<50%) are staying inside QGS and don’t give hadron jets. New formed hadrons catching up them, are excited and throw down excess of energy by soft photons (SP).

We found weak branching of active gluons at 69 GeV/c.

slide12

TSMT– gluons leave QGS and fragment to hadrons

(without branch):

MD = Poisson & Binomial

M - max number of evaporated gluons is rising (from 6 to 10)

max number of hadrons is limited by M*N

(~ 24-26 for charged particles at 69 GeV/c)

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

slide13

102 GeV/c

205 GeV/c

69 GeV/c

405 GeV/c

800 GeV/c

300 GeV/c

slide14

Comparisons:

TSMT -

TSMT

KNO - - - - -

NBD - - - - -

Clan as independent intermediate gluon source.

Semenov S. et al. Sov.J. Nucl Phys.22(1975) 792

A.Giovannini, R.Ugocioni [hep-ph/0405251]

Ln (NBD) ~ Farry (TSMB)

Our results:clans consist from gluons! Change of fragmentation ( ) to recombination mechanism (hh, AA).

Ln (NBD) ~ Binom. (TSMT)

slide15

MD of neutral mesons at 69 GeV/c

The simplification on the second stage of TSM:

Our results:max of neutral mesons = 16

max of total multiplicity =42

Mean multiplicity of neutral mesons versus the number of charged particles

a)

a) top and bottom limits is determined by condition:

b)

b) The noticeable improvement is reached if we decrease top limit at charged multiplicities <10 to

Our result:Centaur events may be realized in the region of HM. AntiCentaur events must be absent.

slide16

pp -> n ch, ISR (30-60 GeV)

Modification.Superposition of clans:

clans consist from one, two (or more) gluons of fission:

62 GeV

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

Kokoulina E., Nikitin V. et al. ISHEPP2004.hep-ph/0503254.

slide17

From GDM the ratio of charged hadrons to neutral mesons in p+p is:

70 GeV/c: 1.19+/-0.25;

800 GeV/c: 1.49+/-0.33;

(cms) 62 GeV : ~ 1.6 ( )

The ratio of h/ p=1.6 is the value measured in experiment : p+p reactions (53 GeV) and

Au-Au (200 GeV/N) peripheral interactions (60-92%) RHIC.

PHENIX [nucl-exp/0410003]; X.Zhang, G.Fai.[hep-ph/0306227]

The assumption:The specific feature of our GDM approach is the dominance of a lot of active gluons at MP. We expect the emergence of them in nucleus collisions (RHIC) and the formation of new kind of matter QGP.

PHENIX

pp

slide18

Soft Photons – the signature of hadronization

The black body emission spectrum:

(the density)

Excess of soft photons:

Our result: L - the size of hadronization region

M.Volkov,E.Kokoulina, E.Kuraev. Part. and Nucl., Let., №5(2004)122. [hep-ph/0402163]

slide19

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

-annihilation (exper.data):

  • The second correlation moment of negative hadrons ( ) in pp-interactions and -annihilation.
  • The differences at 14.75, 22, 32 and 100 GeV/c remain significant for all multiplicities and have local max and min.

GDM:

1)

2)

slide20

GDM

- annihilation (10 – 100 GeV/c)

  • second Correlative moments of negative charged particles:
  • differences between ppand pp inelastic topological cross sections:

__________

_

GDM – 14.75 GeV/c

Pn =

Superposition of intermediate topologies (“0”, “2” –valent q’s, “4”- valent + vacuum q’s)

+ GDM  Pn-description.

slide21

“The search for signatures of quark-gluon dynamics in NN annihilation is somewhatanalogous to the search of the phase transition from a hadron gas to a quark-gluon plasma in relativistic ion transitions. The signal must be isolated from background of statistical processes characteristic of a system with many degrees of freedom. …”

C.Dover. Prog. Part. Nucl. Phys. 29(1992)87.

_

“… series of experimental facts and theoretical ideas which might, hopefully, transform an enigma in a Ariadna thread in the labyrinth of multiparticle dynamics in its awkward journey toward QCD and open new perspectives in pp and heavy ion collisions in the TeV energy domain.”

A.Giovannini (2004).

conclusions outlook
MD charged and neutral (69 - 800 GeV/c) ;

the thermodynamic picture of the gluon escape (evaporation);

the active role of gluons;

the charged hadron/ neutral pion ratio;

estimates of the soft photon number and the size region of emission;

2nd correl. moment in

-annihilation.

the description of MD at higher energies;

the inclusion momentum distribution in TSM;

the investigation of gluon structure of clans;

the employment GDM for the description of - annihilation;

the hA- and AA- processes at 70 GeV/c and higher in the region of high multiplicity.

Conclusions: Outlook:
slide23
There is no higher or lower knowledge, but one only, flowing out of experimentation.

Leonardo da Vinci