Meridians of cooperation

These days filled us with energy and optimism

At the end of September, the annual 53rd International Symposium on Multiparticle Dynamics (ISMD-2025) was held on the island of Corfu, Greece. With the support of VBLHEP Directorate, I was fortunate to participate in it.

The ISMD was first held in Helsinki, Finland, in 1971. Its organizers were B.Buckling, K.Kajanti, G.Satz and D.Tuominemi. It immediately became popular. It is organized and held by a Board of Elders. To obtain the right to host ISMD, a preliminary approval (a "yellow light") is required, followed by the final approval (a "red light"). Symposia are held alternately in countries across Europe, Asia and South or North America.

I first attended the ISMD in 2002, when it was held in Alushta. Its organizer was Professor Laszlo Jenkovski. JINR Directorate provided comprehensive support, essentially covering all financial expenses and organizing the event. Sadly, Laszlo passed away in August of this year.

I was invited to give a talk and to present the results of my investigation of multiplicity in electron-positron annihilation. There, I met the legendary experimental physicist Vladimir Nikitin. At the time, he was preparing the "Thermalization" experimental project to study high-multiplicity events at the U-70 accelerator in Protvino. As a participant in the STAR experiment at BNL, V.A.Nikitin anticipated the future area of high energy physics research related to the investigation of collective phenomena in these events. I was invited to participate in this project that was successfully completed. We registered high-multiplicity events for both charged and neutral particles. We confirmed the production of a pion condensate at a level of seven standard deviations in this field. A gluon dominance prototype was developed to describe multiplicity in hadron interactions.

After the ISMD in Alushta, JINR staff traveled to symposiums in Krakow (Poland, 2003), Kromeriz (Czech Republic, 2005), Paraty (Brazil, 2006), Berkeley (USA, 2007) and Hamburg (Germany, 2008). In 2005, I proposed holding the symposium in Belarus at the Golden Sands sanatorium, as we had many years of experience organizing schools in Gomel.

The following year, to obtain preliminary approval from the Council of Elders, I gave a report in Brazil. Some Western European elders expressed negative views on Belarus. I was confused but I didn't lose hope. A year later, in Berkeley, Nu Shu (STAR, RHIC) supported me, persuading the Europeans to change their minds. During the Gomel School, N.A.Rusakovich, then JINR Scientific Secretary, promised to provide us with partial financial support. In 2008, we were voted in unanimously in Hamburg and the ISMD organizer Hannes Jung congratulated me.

Anyone involved in organizing and hosting conferences is familiar with this challenging yet rewarding work. The preparations were intense but everything went wonderfully, with representatives from over 20 countries attending. The natural surroundings, the communication between the participants, the historic Gomel park and the festive dinner on the riverbank in the rays of the setting sun, all of these left indelible memories for our guests. It's worth noting that former JINR employees from Slovakia and the Czech Republic, as well as our compatriots working abroad, provided invaluable assistance in the preparations.

There followed symposia in Japan, Belgium, Singapore and Santa Fe. In 2020, these were interrupted due to COVID-19, so the Scottish team held the 2021 symposia online. In 2022, after the imposition of sanctions, physicists from Russia and Belarus were denied access, although they were allowed to attend via Zoom.

It seemed that the ISMD traditions, unshakable for half a century, had been broken. But last year, JINR physicists attended a symposium in Hungary and this year, our Institute was represented with two papers. Today, the Council of Elders takes the selection of the symposium venue more seriously. One of the relevant issues for the organizers was obtaining a visa for unimpeded entry into the country.

And finally, I had my first flight through Turkey, then a transfer in Athens and the plane landed on the island of Corfu. It was late evening and a taxi quickly took me to the hotel. I could rest. The next morning, during breakfast, I met with participants from Germany, Italy and China. Unfortunately, not all participants were able to book this hotel, the closest one to the venue.

The sessions were held in a historic building dating back to the 19th century (the summer residence of the British Lord High Commissioner). It is located in a historic park overlooking the sea. The organizer of this year's Symposium was George Zupanos, a specialist in supersymmetry. The majority of participants came from the United States (13) and Germany (12). Physicists from Poland (8), Italy (8), China (7) and Brazil (5) always actively participate. One to three representatives from other countries each attended. Speakers were given 25 minutes per report. The number of questions was limited to three or four. The total number of speakers did not exceed 70. Each participant strictly adhered to the report time limit. The reports were informative and concise, presenting the most important results.

The Symposium programme included the following topics: the evolution of QCD in dense media with the production of hadronic jets, diffraction physics, collective phenomena (jets, flows), the production of particles with high transverse momentum, nucleon structure (small and large), heavy flavors, astrophysics and cosmic rays. The experimental results presented were often measured with greater precision than predicted by theoretical calculations.

After the Symposium closed, the Council of Elders announced the decision to hold the next ISMD in Taiwan in August, 2026. The days spent in Kirker on the island of Corfu filled us with energy and optimism for future research. Here, we met colleagues from other countries and various collaborations. The atmosphere during the Symposium was friendly and no communication barriers arose that is encouraging that the ISMD tradition will continue.

Elena KOKOULINA,
photo courtesy of the author