From 25 to 27 November 2024, the sixth annual International Workshop on Methods of Data Analysis and Processing in Experiments at the NICA Accelerator Complex (NICA-2024) took place online. More than 150 scientists from 14 countries participated in the event. During the three days, they discussed both theoretical and experimental aspects of relativistic heavy-ion collision physics and exchanged experiences and ideas to enhance future research. As always, the workshop was organized by the Joint Institute for Nuclear Research and the National Research Nuclear University Moscow Engineering Physics Institute (NRNU MEPhI).

The first day of NICA-2024 was full of interesting talks. One of the organizers, MPD Collaboration Spokesperson, Chief Researcher at the VBLHEP JINR Elementary Particle Identification Sector Viktor Riabov opened the event. In his welcome speech, he emphasised that the participants come from a wide range of countries: Bangladesh, Brazil, Bulgaria, China, Cuba, the Czech Republic, India, Kazakhstan, Mexico, Russia, Serbia, the USA, Uzbekistan, and Vietnam.

Viktor Riabov noted that the seminar’s scientific programme, consisting of more than 20 presentations, is aimed at a diverse audience of specialists: “The Organizing Committee prepared a programme that is interesting for the widest audience. Some of the talks are educational: they describe analysis methods and result interpretation in detail. This will be useful for both young specialists and experienced scientists, since all of us are constantly improving our knowledge”.

Associate Professor at the MEPhI Department of Experimental Methods of Nuclear Physics, a VBLHEP JINR leading researcher, MPD Collaboration Deputy Spokesperson Arkady Taranenko delivered the first talk. He provided an overview of the results obtained as part of programmes of scanning nuclei interaction energy and colliding system size at the world’s largest accelerator complexes, such as RHIC (BNL, USA), LHC (CERN), FAIR (GSI, Germany), and NICA.

A slide from Arkady Taranenko’s presentation

One of the main purposes of these scanning programmes is to measure anisotropic flow, its fluctuations, and correlation between its harmonics. These characteristics allow obtaining valuable information about the initial conditions of collisions and the evolution of the system, particularly about its transport properties: the equation of state (EOS), the speed of sound (c s), viscosity, etc.

The data in the presentation indicated a strong energy dependence of the anisotropic flow (vn) during heavy ion collisions at NICA in the energy range from 2.5 to 11 GeV, which may indicate a phase transition from hadronic to partonic matter.

Arkady Taranenko noted that the MPD and BM@N (Baryonic Matter at Nuclotron) Collaborations currently have all the necessary software for successful anisotropic flow analysis. “The new data obtained in the BM@N Experiment is very important, as it will allow for additional measurements in this energy range. The first preliminary research results will be published very soon,” the scientist noted.

A researcher at the University of Science and Technology of China (USTC) Fan Si spoke about experimental methods and results of fluctuation measurements at RHIC. He presented new data obtained by the STAR Collaboration as part of the second stage of beam energy scanning (BES-II) at the RHIC Collider. An important result was a significant improvement in measurement accuracy compared to the previous stage of the experiment, BES-I.

A slide from Fan Si’s presentation

Associate Professor ate the High Energy and Particle Physics Department at Saint Petersburg State University Grigory Feofilov discussed centrality determination method using a new modified Monte Carlo Glauber model, which can be implemented in the MPD Experiment in the future.

BM@N Collaboration Spokesperson, VBLHEP JINR Chief Researcher Richard Lednicky discussed the historical development and prospects of the femtoscopy method. In his opinion, it is the coalescence method in femtoscopy that allows obtaining the most valuable information about the characteristics of the matter created in the ongoing and future experiments both at the RHIC and LHC Colliders and the NICA and FAIR Accelerator Complexes.

At the end of the first day, a Kurchatov Institute researcher Dmitry Peresunko spoke about the specifics of the Bose-Einstein correlations of direct photons and the results of their experimental measurements carried out at RHIC and LHC. An USTC Professor Zebo Tang provided a detailed review of the phenomenology of experimental results on heavy quark and quarkonium production in heavy ion collisions. A Professor at the Institute of Nuclear Sciences at the Mexican National Autonomous University of Mexico (ICN-UNAM) Alejandro Ayala shared the latest results of theoretical heavy ion physics studies.

On 26 and 27 November, the seminar participants heard and discussed 14 more detailed talks on a wide range of experimental and theoretical problems in modern heavy ion physics.

Every day’s programme finished with a session aimed at detailed discussions of the presentations and free exchange of opinions. The participants’ questions, asked in an online chat, were collected and systemathised by the moderators for further analysis.

The sixth NICA-2024 international online seminar was held with the support of the Ministry of Science and Higher Education of the Russian Federation as part of the “Priority 2030” and “Fundamental and applied research at the NICA Experimental Megascience Complex” projects.