A multinational team of physicists, including scientists from the Weizmann Institute: "The signs are increasing that we have succeeded in reconstructing the primordial matter created immediately after the Big Bang"
460 physicists, from 57 research institutes operating in 12 countries announced that from an analysis of the results obtained so far in the experiment they are performing jointly, a clear hint emerges that they succeeded in reproducing the primordial material, called "quark-gluon plasma", which was created immediately after the big bang, and which later formed the source of the formation of matter as we know it today. The experiment, known as "Phoenix" is being carried out at the American National Laboratory in Brookhaven on Long Island, New York and physicists from Brazil, China, France, Germany, Hungary, India, Israel, Japan, South Korea, Russia, Sweden and the United States are participating in it. The Israeli group participating in the project is headed by Prof. Yitzhak Tsaroya, head of the particle physics department at the Weizmann Institute of Science. Prof. Tsaroya and the members of his research group designed and built special particle detectors that are an essential part of the detector array in the "Phoenix" experiment.
In the first millionth of a second after the big bang, there were no atoms of different materials in the universe, as they are known to us today. In fact, at that time the protons and neutrons were not yet "born" either. The jets of hot matter that spread everywhere in the first fractions of a second of the universe's existence contained a rare mixture of quarks and free gluons (known as "quark-gluon plasma"). Later, when the universe cooled down a little and the density in it decreased, the quarks and gluons "organized" in different combinations that created more complex particles, such as protons and neutrons. Since then, in fact, no free quarks and gluons have been seen in the universe.
Scientists seeking to study the unique physical properties of quark-gluon plasma are therefore trying to recreate this primordial mixture of matter using a purpose-built particle accelerator called RHIC at Brookhaven National Laboratory on Long Island, New York. This special accelerator creates two beams of gold ions, accelerates them against each other and causes a head-on collision between them. From the intensity of the collision (about 40 trillion electron volts), part of the movement energy of the gold ion beams turns into heat, while another part of the movement energy turns into different matter particles (a process described in Albert Einstein's famous formula for the equality of matter and energy: E=Mc2). The first stage in the formation of the new particles from the movement energy of the gold ion beams, just like the first stage in the formation of matter in the Big Bang, should be the stage of existence of a quark-gluon plasma.
One of the ways to identify a quark-gluon plasma is based on monitoring the behavior of jets of matter that penetrate it. When a single quark penetrates ordinary matter (containing protons and neutrons), it emits radiation that slows its progress to some extent. Conversely, the rate of deceleration of the same jet, when it penetrates matter that is in the quark-gluon plasma configuration, will be much greater (that is, it will slow down to a greater extent). This is exactly the phenomenon that was recently observed and analyzed in the "Phoenix" experiment that is being carried out at the Brookhaven Laboratory. These findings, say the physicists performing the experiment, are a real hint that we have managed to reproduce the first stage in the formation of matter in the universe called "quark-gluon plasma".
The detectors designed and built by Prof. Tzarua are able to provide independent XNUMXD information on the positions of the particles that are ejected from the collision zone, and according to their direction, energy and identity of these particles, it is possible to learn about the state of matter in the collision zone. The team involved in the development and production of these unique detectors, in addition to Prof. Tsaroy, also Prof. Zev Frankel, Dr. Ilya Rabinowitz, postdoctoral researcher Wei Shi (from China) and research students Alexander Kozlov, Alexander Milov, and Alexander Charlin, all from the Department of Physics of particles at the Weizmann Institute of Science.
