Role of String Fusion Mechanism in Fluctuation Studies

• Published in: Physics of atomic nuclei 2022-12, Vol.85 (6), p.1063-1070
• Main Authors: Prokhorova, D., Andronov, E.
• Format: Article
• Language: English
• Subjects: Analysis; Critical point; ELEMENTARY PARTICLES AND FIELDS/Theory; Gluons; Initial conditions; Monte Carlo method; Monte Carlo simulation; Particle and Nuclear Physics; Particle production; Physics; Physics and Astronomy; Quarks; Strings
• ISSN: 1063-7788; 1562-692X
• DOI: 10.1134/S1063778823010465

In the search for the critical point of strongly interacting matter, one of the key tools is to look at event-by-event fluctuations of different event observables expecting their non-monotonic behavior. It is crucial for the experiments to eliminate an influence of the trivial volume fluctuations on the physics observables of interest. This may be done by an application of the accurate centrality selection and by means of special measures using different estimators of initial conditions. It is also feasible to apply some theoretical approaches in estimation of all the possible sources of unwanted fluctuations. In this paper, we present results obtained in the developed Monte-Carlo model of particle production with particle emitting sources being interacting quark–gluon strings of finite length in rapidity space. Implemented strings dynamics in rapidity causes non-uniform string density over it and brings fluctuations to the system event-wise. The model also takes into account, event-by-event, the string fusion phenomenon caused by string overlap in the transverse plane. It is this process of fusion that modifies string fragmentation characteristics and changes the mean values of multiplicities and transverse momenta of produced particles. Using this model and Monte-Carlo event generator PYTHIA, the calculations were done for the strongly intensive quantities , and .