Multiparticle production continues to attract attention of physicists as in the experimental as in theoretical studies. Up to now no generator can describe data at different energies in full. Quantum chromodynamics calculates high energy interactions in the language of quarks and gluons. The transition to observable hadrons is extremely difficult, since pQCD is not applicable to that region. This project offers to apply the gluon dominance model (GDM) which describes multiplicity distributions (MD) in hadron interactions. It's based on two stages. First stage describes the quark-gluon cascade. The second one is hadronization. It's described phenomenologically. Based on data on pp interactions in the region of high multiplicity (the Thermalization project), within the framework of Gluon Dominance Model, the active role of the gluon component in the formation of secondary particles is confirmed. The ratio of two contributions, emission of a gluon by a quark to its fission is estimated. A number of collective phenomena are observed in this region: the formation of a pion (Bose-Einstein) condensate, signals that we interpret as Cherenkov radiation of gluons, the disappearance of leading particles. The study of gluon structure of the proton and search for collective phenomena in pp collisions can be performed at the SPD facility of the future NICA collider (JINR, Dubna).
Tasks
1) Calculations of multiplicity distribution for charged particles in proton-proton collisions at high energy in framework of Gluon Dominance Model (GDM).
2) Calculations of an averaged multiplicity and a variance in GDM for pp interactions.
3) Fitting of experimental data by the built MD in GDM.
4) Calculations of multiplicity distribution for charged particles in proton-antiproton annihilation at high energy in framework of Gluon Dominance Model.
5) The estimation the contribution of the exchanged charge in pp interaction.
6) Calculation of the second correlation moment f2, the factorial and the factorial cumulative moments by using MD and/or the generation function G(z) for pp and ppbar interactions
Preliminary schedule by topics/tasks
(1st week) Calculations of multiplicity distribution for charged particles in proton-proton collisions at high energy in framework of Gluon Dominance Model (GDM).
(2nd week) Calculations of an averaged multiplicity and a variance in GDM for pp interactions.
(3rd week) Fitting of experimental data by the built MD in GDM.
(4th week) Calculations of multiplicity distribution for charged particles in proton-antiproton annihilation at high energy in framework of Gluon Dominance Model.
(5th week) The estimation the contribution of the exchanged charge in pp interaction.
(6th week) Calculation of the second correlative moments f2 = n(n-1) -n^2, the factorial and the factorial cumulative moments by using MD and/or the generation function G(z) for pp and ppbar interactions
Required skills
Good knowledge of C++ programming language and the ROOT software (http://root.cern.ch) is greeted.
Acquired skills and experience
Theory of probability and mathematical statistics, quantum chromodynamics, tools in the experiment, NICA project
Recommended literature
1. Ernest M Henley, and Alejandro Garcia. Subatomic Physics. — University of Washington, USA. World Scientific, 2010.
2. Dokshitzer Yu. L. QCD phenomenology. Lectures at the CERN-Dubna school. Pylos, August 2002. // — 2003. — arXiv:0306287 [hep-ph].
3. Dremin I.M. Multiparticle production and quantum chromodynamics. (2002) [hep-ph/0203024];
4. Politzer H.P. Phys.Rep. 14(1974)129.
5. Particle Data Group, Barnett R.M. et al. Phys.Rev.D54(1996)1.
6. Kokoulina Е.С. Analysis of multiparticle dynamics in e+e−-annihilation into hadrons by two-stage model // Proceedings, XXXII International Symposium on Multiparticle Dynamics, Alushta, Ukraine, September, 2002. — 2003 — World Scientific. — P. 340–343.
7. Rushbrooke J.G. and Webber B.R. High energy antiparticle-particle reac- tion differences and annihilations // Phys. Rep. — 1978. — V.44, no. 1. — P. 1–92.
8. Konishi K., Ukawa A., Veneciano G. Nucl.Phys. B157(1979)45.
9. Giovannini A. Nucl.Phys. B161(1979)429. 10. https://nica.jinr.ru
