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Е. Кокоулина, А. Кутов *) , В. Никитин и Ю. Петухов

Поиск коллективных явлений в адронных взаимодействиях. Е. Кокоулина, А. Кутов *) , В. Никитин и Ю. Петухов СВД -2 Коллаборация: JINR, IHEP and SINP MSU *) ОМ УрО РАН, Сыктывкар. Gold Sands , Belarus, September , 4-9, 200 9. Outline.

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Е. Кокоулина, А. Кутов *) , В. Никитин и Ю. Петухов

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  1. Поиск коллективных явлений в адронных взаимодействиях Е. Кокоулина, А. Кутов*), В. Никитин и Ю. Петухов СВД -2 Коллаборация: JINR, IHEP and SINP MSU *) ОМ УрО РАН, Сыктывкар Gold Sands, Belarus, September ,4-9, 2009

  2. Outline • The extreme multiplicity puzzles • SVD-2 setup and data processing • Search of the collective phenomena • Gluon Dominance Model • Outlook

  3. The extreme multiplicity puzzles

  4. The extreme multiplicity puzzles • MC PHYTHIA code has shown that standard generator predicts a value of the cross section which is in reasonably good agreement with data at small multiplicity nch < 10, but it underestimates the value σ(nch) by two orders of the magnitude at nch > 18. • The existing models are very much sensitive in the region of the extreme, more significantly than mean multiplicity (ExMu). • The various manifestation of the collective phenomena is caused by the dense system formation at the ExMu region.

  5. SVD-2 setup and data processing

  6. SVD-2 setup U-70 acceleration at IHEP (Protvino), 50-70 GeV. The trigger system selects the rare events with the charged multiplicity more than 20 - 30. The suppression factor of events with lower multiplicity amounts about 104. The Target itself is a 7-cm thick, 25mm-diameter vessel for liquid hydrogen. EMC 10 m MS DT MSVD Č ScH MicroStrip Vertex Detector Scintillator HodoscopeDrift Tube Tracker Magnetic Spectrometer Cherenkov counter ElectroMagnetic Calorimeter

  7. Software development • MC event generator is designedfor the setup element simulation; • Data processing software for ExMu; • Alignment; • GEANT-3 program reconstruction analysis.

  8. Software development Multiplicity Distributions (MD) in pp interactions at different trigger levels: 8, 10, 12. run 2008,PVD.

  9. Software development Kalman Filter as Track Fitter for SVD • Drift tubes calibration - from raw TDC time to drift distance. • Recognize track candidates – find track-like groups of hits: pattern recognition. • Taking into account REALITY: alignment. • From track candidates to real track parameters: track fitting. • From tracks to vertexes: vertex fitting

  10. Software development Track fitting • It is necessary to take into account: • - non-uniform magnetic field (from table); • - multiple scattering; • - energy losses.

  11. Software development Analysis sequence • VD + MS reconstruction: track parameter determination; use MS data for momentum estimation. • DT track finding separately in Y,U,V planes, then build 3D tracks. • DT + MS track fitting: track parameters from 1 or 2 as initial values and Kalman Filtering procedure. • 4. Taking into account non-uniform magnetic field, • multiple scattering, energy losses. • 5. Re-fit vertexes, if it is necessary. • 6. Kinematical fit (we can use the Vt++ library)‏

  12. Software development

  13. Software development

  14. Search of the collective phenomena

  15. Search of the collective phenomena • 1. Bose-Einstein Condensation (BEC); • Ring Events (Cherenkov gluon emission); • Gluon Dominance Model (GDM); • Excess of soft photon (SP) yield; • Clusterization; • Turbulence Phenomena …

  16. Search of the collective phenomena Bose-Einstein Condensation M. Gorenstein andV. Begun had predicted an abrupt and anomalous increase of the scaled variance ωof neutral- and charged- pion-number fluctuations in the vicinity of the BEC line [Phys.Lett.B651:114 (2007)].

  17. Search of the collective phenomena Ring Events in pp (n_ch >8), run 2008 Red - 7th order Polynomial nch  9 nch < 9

  18. Search of the collective phenomena Monte-Carlo (nch  9)

  19. Search of the collective phenomena Ring Events Our experiment: n - the index of the refraction, θC = 0.065  0.005, n = 1.0023 ± 0.0003 Theory: n (p) = 1+Δn (p) = 1+3mpr2 σ(p) nhρ(p) / 8πppr, nh – the number of scatters, ρ = Re F/ Im F, Δn (p) = 3 mp3 Re F / 2p 2 = 0.0005 * Re F, at Re F =4.6 GeV (.92 fm)

  20. Gluon Dominance Model

  21. Gluon Dominance Model Second stage (hadronization): BD First stage (cascade): a) gluon fission; b) quark bremsstrahlung; c) quark pair creation; NBD. A.Giovannini. NP, B161 (1979). Convolution of two stages.

  22. Gluon Dominance Model GDM parameters: mean multiplicity of hadrons from 1 gluon while its passing throughof hadronization stage remains constant ~1 (14 -189, GeV). Fragmentation mechanism of hadronization: 1 parton to 1 hadron. B.Muller [nucl-th/0404015]

  23. Gluon Dominance Model GDM had shown:quarks of initial protons are stayingin leading particles (from 70 to 800 GeV/c). Multiparticle production is realizedby gluons. We name them active ones. Two schemes: with/without gluon branch. Convolution gluon (Poisson/Farry) & hadron (PBD) MDs. pp–interactions

  24. Gluon Dominance Model recombination mechanism of hadronization in pp–interactions B.Muller [nucl-th/0404015]

  25. Gluon Dominance Model In GDM for pp at 70 GeVthe maximal possible number of new formed charged, neutral & total hadrons is limited and is equal to 26, 16 and 42 particles, accordingly. Preliminary experimental data corroborate these predictions. From PVD data (which has constricted acceptance) we see events with maximal multiplicity 24 charged particles only.

  26. Gluon Dominance Model Soft Photons (SP) At HE σ(SP) are 5-8 times more in the comparison with the QED predictions. Assumption: QG system or excited new formed hadrons set in almost equilibrium state during a short period (we use the black body emission spectrum): Estimations of SP emission region: 4-6 fm.

  27. GDM and experimental MD’s Mirabel: ■- 50 GeV  - 70 GeV SVD:  - 50 GeV - GDM Run 2008, 50 GeV pp interactions 8th level HM trigger preliminary

  28. Outlook • Software check-out for track reconstruction in DT and MS with tracks reconstructed in PVD. • The continuation of the searching of the collective phenomena in pp (pA) interactions at the extreme multiplicity: the Bose-Einstein condensation, ring events (dense groups in angle distributions), clusterization, turbulence phenomena. • Soft photon studies

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