Specialization: 010700/17 Theoretical and mathematical physics
Program: 28: Elementary particles interaction theory and quantum field theory
Head program: prof. M. A. Braun
High Energy and Elementary Particles Physics Department
Scientific supervisor: prof. V. V. Vechernin
Reviewer: M. A. Braun

Monte-Carlo model with the fusion of colour strings
for pp and AA interactions at LHC energies
V.N. Kovalenko

The soft pp and AA interactions at high energy are considered in the framework of phenomenological model with the colour strings formation and fusion. Elementary parton collisions are assumed to be realized as the interaction of  two colour dipoles from projectile and target nucleons. Modelling of the exclusive parton distributions of momentum fraction and transverse coordinates is performed. The interaction of colour strings in transverse plane was carried out in the framework of locale string fusion model taking into account finite rapidity width of strings. The parameters were fixed with experimental data on pp total inelastic cross section and charged multiplicity.
Long-range correlation functions between multiplicity, mean transverse momentum  in different rapidity windows was calculated for the LHC energies and n-n, pt-n, pt-pt correlation coefficients were determined and compared with preliminary ALICE experimental data. Dependence of such correlations on the width and position of backward and forward rapidity windows was also studied.
Using of pp model as the basis of nucleon-nucleon collisions the model of Pb-Pb interaction was developed that does not require use of Glauber's picture of elementary collisions. Charged multiplicity, number of participant nucleons and binary collisions and their variations were computed and compared with predictions of alternative models and experimental data. The influence of different ways of centrality determination on multiplicity fluctuations and long-range correlations was estimated. 

Список публикаций
1. V. Kovalenko. Modelling of exclusive parton distributions and pp interaction features in the approach with the colour strings formation // Conference  Proceedings International Student Conference "Science and Progress" — St.Petersburg,  2010. P. 257-261