Scientific popular summary of my work

The scientific aim of my work is to perform the studies of heavy-ion collisions in an unexplored so far range of collision energy of the order of several or several tens of GeV using the femtoscopy method in close collaboration of scientists involved in experiments as STAR, CBM, HADES.

The results of nearly three decades of studying the relativistic heavy-ion collisions, and in particular, the decade associated with the use of the largest collectors: LHC at CERN and RHIC at BNL, led to the creation of a new state of matter in which the so-called quark degrees of freedom, or the smallest, yet indivisible components of matter. However, the results obtained so far concerned the conditions for high temperature and low baryon density values, when the proportions of baryons and anti-baryons are almost identical. With smaller collision energies of elementary particles and heavy ions, it is possible to explore the properties of matter with lower temperature and higher baryon density values.

The general physics goal is to explore the QCD phase diagram in so far unexplored region relevant for one of the hottest recent topics related to phase transition between Hadron Gas (HG) and Quark-Gluon Plasma (QGP) and to the Critical Point (CP). Studies are performed by analyzing particle correlations in the frame of the Beam Energy Scan (BES) program – in the frame of STAR, HADES, and CMB experiments. We investigate unexplored so far region of the mixed-phase of hadronic matter in close collaboration in the mentioned above experiments.

These studies fill a missing gap between measurements obtained for collision energies of the order of few MeV (e.g., GANIL) and researches for collision energies of the order of several hundreds of GeV (RHIC) or even TeV (LHC). Understanding the QCD phase diagram is one of the most important goals of relativistic heavy-ion physics. Several methods are proposed first-order phase transition between the hadron gas and quark-gluon plasma and/or to find a possible location of the critical point. Here we focus on particle correlations, which is our original contribution. By measuring particle correlations in the region of small relative velocities, the space-time information can be extracted. This method, called correlation femtoscopy, is widely used in the studies of heavy-ion collisions. Femtoscopy is related to the Femto scale (1 fm), which can not be accessed by any other experimental technique. The effects expected here are an essential element of our knowledge about the structure and properties of matter. If the results show unexpected phenomena, it will be open to new research directions in nuclear reactions' physics. The results of this research also have a direct reference to understanding the first moments of the universe's evolution.