Their efforts are focused on mapping the “primordial soup” that filled the universe in its first millionth of a second.
Physicists at Eötvös Lorand University have been using three of the world’s most advanced particle accelerators to study the constituents of atomic nuclei. Their research aims to investigate the “primordial soup” that existed during the first microseconds of the universe’s creation. Interestingly, their findings show that the observed particle movements are similar to the prey search of marine predators, patterns of climate change, and fluctuations in the stock market.
Immediately after that, big bang, the temperatures were so extreme that the nucleus of an atom could not exist, nor could its constituent parts, the nucleons. So in this first example, the universe was filled with a “primordial soup” of quarks and gluons.
As the universe cooled, this medium underwent “freezing,” leading to the formation of particles such as protons and neutrons that we know today. This phenomenon is reproduced on a much smaller scale in particle accelerator experiments, where small droplets of quark matter are produced by collisions between two atomic nuclei. These droplets eventually transform into normal matter by freezing. This change is known to the researchers conducting the experiment.
Changes in quark matter
However, the properties of quark matter change due to differences in pressure and temperature caused by the collision energy of particle accelerators. This change involves “scanning” matter in particle accelerators of different energies, the Relativistic Heavy Ion Collider (RHIC) in the United States, and the Superproton Synchrotron (SPS) and Large Hadron Collider (LHC) in Switzerland. measurements are required.
“This aspect is so important that new accelerators are being built all over the world, including in Germany and Japan, specifically for such experiments. Perhaps the most important question is how does the transition between phases occur? A critical point may appear on the phase map,” explains Mate Sanad, professor of physics at the Department of Nuclear Physics at Eötvös Lorand University (ELTE).
The long-term goal of the research is to deepen our understanding of the strong interactions that govern the interactions between quark matter and atomic nuclei. Our current level of knowledge in this field can be likened to humanity’s understanding of electricity in the time of Volta, Maxwell, or Faraday. They had a concept of basic equations, but a significant amount of experimental and theoretical research is required to develop technologies that significantly change everyday life, from light bulbs to televisions, telephones, computers, and the Internet. was. Similarly, our understanding of strong interactions is still in its infancy, making research exploring and mapping them critical.
Femtoscope innovation
ELTE researchers have been involved in experiments at each of the accelerators mentioned above, and their work over the past few years has provided a comprehensive picture of the geometry of quark matter. They achieved this by applying femtoscope technology. The technique exploits correlations arising from the non-classical, quantum wave nature of the particles produced, ultimately revealing the femtometer-scale structure of the medium from which the particles are emitted.
“For the past several decades, femtoscopes have operated on the assumption that quark matter follows a normal distribution, a Gaussian shape found in so many places in nature,” said one of the group’s principal researchers. , explains Marton Nagy.
However, Hungarian researchers have developed a more general framework, the Léwy process, which is also well known in various scientific fields and successfully explains the search for prey by marine predators, stock market processes, and even climate change. I paid attention to. A feature of these processes is that very large changes occur at a given moment (for example, when a shark searches for food in a new area), and in such cases a Lévy distribution rather than a normal (Gaussian) distribution is used. may occur.
Meaning and role of ELTE
This study is very important for several reasons. Primarily, one of the most studied features of the freezing of quark matter, its transformation into conventional (hadronic) matter, is the femtoscopic radius (noting its relationship with the well-known Hanbury-Brown and Twiss effects). , also called HBT radius). (in astronomy), obtained from femtoscope measurements. However, this scale depends on the assumed shape of the medium. Daniel Kinseth, a postdoctoral fellow in the group, summarizes: “If the Gaussian assumption is not optimal, the most accurate results from these studies can only be obtained under the Lévy assumption. The value of the ‘Lévy index’, which characterizes the Lévy distribution, may also elucidate the nature of the phase transition. There is a gender. Therefore, its variation with collision energy provides valuable insight into the different phases of quark matter. ”
ELTE researchers are actively participating in four experiments: NA61/SHINE at the SPS accelerator, PHENIX and STAR at the RHIC, and CMS at the LHC. ELTE’s NA61/SHINE group is led by Yoshikazu Nagai, and the CMS group is led by his girlfriend Gabriella Pásztor. and his RHIC group by Máté Csanád, who is also coordinating ELTE’s femtoscopic studies.
These groups make significant contributions to the success of experiments in a variety of capacities, from detector development to data acquisition and analysis. They are also engaged in many projects and theoretical research. “What is unique about our femtoscope study is that it is performed in four experiments in three particle accelerators. This gives us a broad view of the geometry and possible phases of quark matter. ”Mate Sanad said.
References: “A new method for calculating Bose-Einstein correlation functions using Coulomb final state interactions” by Márton Nagy, Aletta Purzsa, Máté Csanád, Dániel Kincses, November 8, 2023. European Physics Journal C.
DOI: 10.1140/epjc/s10052-023-12161-y