1 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

2 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. -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 1 st stage, modification of 2 nd scheme by clan mechanism at higher energies; -annihilation (~ GeV/c). Kuvshinov V. and Kokoulina E. Acta Phys.Polon.B13(1982) n

3 First stage (cascade): a) gluon fission; b) quark bremsstrahlung; c) quark pair creation. Second stage: Hadronization. BD Convolution: of two stages quark fission -> NBD K.Konishi et.al.NPB157(1979)45 A.Giovannini.NPB161(1979)429.

4 Pn in -annihilation at 14, 50, 91.4, 172 and 189 GeV; H(q) at 91.4 GeV. 14GeV 50GeV 91.4GeV 172GeV 189GeV 91.4GeV Pn H(q) E. Kokoulina. Minsk, NPCS (2002)[hep-ph/ ]; ISMD32,2002.

5 hadronization gluon parameters ( ), GeV. maximal (mean) multiplicity of hadrons are formed from gluon on the stage of hadronization. hadronization of gluon are softer than quark.

6 “THERMALIZATION” Project “THERMALIZATION” (JINR, IHEP, SINP MSU, GGTU) 1.Experimental data pp (70 GeV). 2.Quark model. Yad.Fiz. 55 (1992) 820. Collisions of quark pair. 3.MC PHYTHIA code underestimates the s (nch) by two orders of magnitude at nch=18. nch=18 The study of MP at pp (pA) interactions in HM region: nch> The goal:

7 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.

8 Our model investigations 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. 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).

9 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. 7 th Int. school-seminar The actual problems of Microworld Physics, Gomel, Belarus V.1 (2004) [hep-ph/ ]

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

11 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.

12 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 (~ for charged particles at 69 GeV/c) Kokoulina E. Acta Phys.Polon. B35(2004)295

13 69 GeV/c 102 GeV/c205 GeV/c 405 GeV/c800 GeV/c 300 GeV/c

14 Semenov S. et al. Sov.J. Nucl Phys.22(1975) 792 TSMT - KNO A.Giovannini, R.Ugocioni [hep-ph/ ] NBD TSMT Clan as independent intermediate gluon source. Ln (NBD) ~ Farry (TSMB) Ln (NBD) ~ Binom. (TSMT) Our results: clans consist from gluons! Change of fragmentation ( ) to recombination mechanism (hh, AA). Comparisons:

15 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) top and bottom limits is determined by condition: 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. a) b)

16 pp -> n ch, ISR (30-60 GeV) Modification. Superposition of clans: clans consist from one, two (or more) gluons of fission: 62 GeV Kokoulina E., Nikitin V. et al. ISHEPP2004.hep-ph/ Soft ( ) & semi-hard ( ) components, and so on.

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

18 Soft Photons – the signature of hadronization The black body emission spectrum: Excess of soft photons: (the density) L(fm) Our result: L - the size of hadronization region M.Volkov,E.Kokoulina, E.Kuraev. Part. and Nucl., Let., №5(2004)122. [hep-ph/ ]

19 -annihilation (exper.data): 1)The second correlation moment of negative hadrons ( ) in pp-interactions and -annihilation. 2)The differences at 14.75, 22, 32 and 100 GeV/c remain significant for all multiplicities and have local max and min. J.Rushbrooke and B.Webber. Phys.Rep. C44(1978)1 1) 2) GDM:

20 GDM - annihilation (10 – 100 GeV/c) GDM – GeV/c Pn = a)second Correlative moments of negative charged particles: b)differences between pp and pp inelastic topological cross sections: __________ Superposition of intermediate topologies (“0”, “2” –valent q’s, “4”- valent + vacuum q’s) + GDM  Pn-description. _

21 _ “The search for signatures of quark-gluon dynamics in NN annihilation is somewhat analogous 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).

22 Conclusions: Outlook: MD charged and neutral ( 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; 2 nd 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.

23 There is no higher or lower knowledge, but one only, flowing out of experimentation. Leonardo da Vinci