Recently, the European Organization for Nuclear Research (CERN) presented a conceptual design for the Future Circular Collider (FCC), which should replace the Large Hadron Collider. The concept envisages the creation of a 100 km long tunnel in the vicinity of Geneva, in which it is planned to sequentially place accelerator rings to work with beams of various types: from electrons to heavy nuclei. Why do physicists need a new collider, what tasks it will solve, and what role scientists from Russia play in this, Vitaly Okorokov, a participant in the FCC project, professor at the National Research Nuclear University MEPhI (NRNU MEPhI), told RIA Novosti correspondent.
- Vitaly Alekseevich, why do physicists need the Future Ring Collider?- The FCC project is one of the most important points of the new edition of the European Strategy for Particle Physics, which is being formed today. Scientists from Russia participate in international projects in this area of fundamental science, both in research at colliders and in non-accelerator experiments. In modern physics, the world of elementary particles is described by the so-called Standard Model - quantum field theory, which includes electromagnetic, strong and weak interactions. The composition of fundamental particles in this model was fully experimentally confirmed with the discovery of the Higgs boson in 2012 at the Large Hadron Collider (LHC). However, answers to many important questions, for example, about the nature of dark matter, about the emergence of asymmetry of matter and antimatter in the observable Universe, and so on, are beyond the scope of the Standard Model. To find solutions to key problems in fundamental physics, scientists are designing new, ever more powerful accelerator complexes. - What tasks will the Future Ring Collider solve? - This is the measurement of the parameters of the Standard Model with an unattainable accuracy before, a detailed study of phase transitions and properties of matter taking place in the very early Universe under extreme conditions, the search for signals of new physics outside the Standard Model, including dark matter particles. From the point of view of physics, it is very interesting to study the properties of strong interaction at ultrahigh energies and to develop a theory describing it - quantum chromodynamics.- What tasks will the Future Ring Collider solve? - This is the measurement of the parameters of the Standard Model with an unattainable accuracy before, a detailed study of phase transitions and properties of matter taking place in the very early Universe under extreme conditions, the search for signals of new physics outside the Standard Model, including dark matter particles. From the point of view of physics, it is very interesting to study the properties of strong interaction at ultrahigh energies and to develop a theory describing it - quantum chromodynamics.- What tasks will the Future Ring Collider solve? - This is the measurement of the parameters of the Standard Model with an unattainable accuracy before, a detailed study of phase transitions and properties of matter taking place in the very early Universe under extreme conditions, the search for signals of new physics outside the Standard Model, including dark matter particles. From the point of view of physics, it is very interesting to study the properties of strong interaction at ultrahigh energies and to develop a theory describing it - quantum chromodynamics.it is very interesting to study the properties of strong interaction at ultrahigh energies and to develop a theory describing it - quantum chromodynamics.it is very interesting to study the properties of strong interaction at ultrahigh energies and to develop a theory describing it - quantum chromodynamics.- What is the essence of this theory?- According to it, particles called hadrons, for example, protons and neutrons, have a complex internal structure formed by quarks and gluons - the fundamental particles of the Standard Model involved in strong interactions. According to existing concepts, quarks and gluons are confined inside hadrons and, even under extreme conditions, can be quasi-free only on linear scales of the order of the size of an atomic nucleus. This is a key feature of strong interaction, which has been confirmed by a large number of experimental and theoretical studies. However, the mechanism of this most important phenomenon - the confinement of quarks and gluons (confinement) - has not yet been determined. For several decades, the problem of confinement has invariably been included in all sorts of lists of the main unsolved problems of fundamental physics. Within the framework of the FCC project, it is planned to obtain new experimental data and significantly advance in understanding the properties of strong interactions, in particular, confinement.- What tools are supposed to solve these problems?- An integrated approach is used to carry out an extensive research program, according to which the FCC project includes two stages. The first stage "FCC-ee" involves the creation of an electron-positron collider with a beam energy in the range from 44 to 182.5 gigaelectronvolts. At the second stage "FCC-hh" experiments will be carried out on colliding beams of protons and nuclei. In this case, it is supposed to accelerate protons to an energy of 50 teraelectronvolts and heavy nuclei (lead) - to 19.5 teraelectronvolts. This is more than seven times the energies achieved at the most powerful operating complex of the LHC. It is planned to use it, along with the entire existing infrastructure, to obtain beams of accelerated particles before their introduction into the main 100-kilometer ring of the new collider FCC-hh. The construction of an external linear electron accelerator with an energy of 60 gigaelectronvolts will make it possible to implement a program for a detailed study of the internal structure of a proton using deep inelastic electron-proton scattering (FCC – eh).- The development and construction of installations of this level takes decades. When will construction start? When are the first scientific results expected to be obtained?- If the concept is adopted, the start of the implementation of the FCC integral program is planned around 2020. The construction of the FCC-ee lepton collider will take about 18 years, with a subsequent work duration of about 15 years. It turns out that the duration of the first stage will be about 35 years. During the operation of the FCC-ee, preparation of the second stage of the project will begin. In accordance with the concept, within ten years after the end of the FCC-ee operation, it will be dismantled, the hadron collider ring will be erected and detectors installed. Obtaining new data for proton and nuclear beams is planned for the middle of 2060. The duration of the FCC operation with proton and nuclear beams is planned for about 25 years, and the total duration of the second stage is about 35 years. Thus, it is assumed that experiments at the FCC will continue until the end of the 21st century. This project will be truly global.
What role do scientists from Russia, in particular, from NRNU MEPhI play in the FCC project?
- NRNU MEPhI, together with other Russian organizations, actively participates in the FCC project and carries out scientific work both for the physical program of future research and for the accelerator complex.
Scientists of NRNU MEPhI made a contribution to the FCC concept, in particular, in the first volume, which contains a description of the general physical program for all planned types of beams, and in the third volume, devoted to research with proton and nuclear beams (FCC – hh).
- Tell us in more detail, please
- As mentioned above, at extremely high temperatures (hundreds of thousands of times higher than at the center of the Sun) and energy densities, quarks and gluons can become quasi-free on nuclear scales, forming a new state of matter, which is usually called quark-gluon plasma.
Collisions of beams of protons and various nuclei at ultrahigh energies of the FCC-hh collider will make it possible to study, in particular, the collective properties of quark-gluon matter formed during interactions of both large systems (heavy nuclei) and small (proton-proton, proton-nucleus), providing unique conditions for studying the properties of many-particle states.
The planned for FCC-hh, significant, compared to the LHC, increase in the energy and integral luminosity of beams opens up qualitatively new possibilities for studying, for example, the behavior of the heaviest fundamental particles of the Standard Model - the Higgs boson (about 125 times heavier than a proton) and a t-quark (heavier than a proton about 175 times) - in hot and dense quark-gluon matter, as well as their possible use as "probes" to determine the properties of this matter.
Promotional video:
In the summer of 2014, during a discussion at the Institute for High Energy Physics. A. A. Logunov of the National Research Center "Kurchatov Institute" a proposal was put forward to use the Higgs bosons to study the properties of quark-gluon matter. This proposal was included as one of the items in the program of research with beams of heavy nuclei at the FCC. In my opinion, this direction is of considerable interest for the physics of strong interactions.
We have only touched on some aspects of future research. The FCC's scientific program is very extensive and work under this project is ongoing.