Grant supporting research teams for AGH University scientist

Project description

All known elementary particles and interactions (except for gravity) are included in the so-called Standard Model. It provides a mathematical description of these forces with the use of quantum fields. In addition to electromagnetic interactions known from everyday life, described by electron and photon fields, and the so-called weak interactions, which are responsible for certain radioactive decays, among other things, the Standard Model describes strong interactions that govern the structure of hadrons, i.e. particles made up of quarks and gluons. The theory of quark-gluon interactions itself is called quantum chromodynamics (QCD). Quarks are particles that are somewhat similar to electrons, but in addition to a smaller (fractional) electric charge, they have an additional type of charge called colour. Gluons exchange colour between quarks, which means that they are responsible for the colour interactions of quarks. Moreover, gluons may interact with each other, which makes the QCD theory truly complicated. An interesting aspect of the theory is that particles made up of quarks and gluons observed in nature are colourless. This is called colour confinement.

Another characteristic of hadrons, directly related to the topic of the project, is their mysterious behaviour in collisions at near-light speed. Let us imagine a particle sampling such a speeding hadron. It may be a quark, a gluon from another speeding hadron, or a photon. A sampling particle typically collides with a quark or gluon, but it turns out that the density of gluons increases rapidly with collision energy until the gluons dominate and ‘fill’ the entire hadron. One might ask what will happen if we continue to increase the energy? Theoretical calculations show that gluons create some kind of a condensate that has certain collective properties. When the energy further and further, the density of gluons stops to grow; this is the so-called gluon saturation. The phenomenon is related to the fundamental property of gluon fields which are governed by non-linear field equations. The most important experiment with hadrons accelerated to very high speed is the Large Hadron Collider (LHC) at CERN; however, not each collision occurs with the participation of hadron in the state of gluon saturation. Such cases may be filtered with the use of detectors (more specifically, their part called calorimeter) of particles produced at small angles. Some of the detectors are to be extended by such high-resolution calorimeters. Another key experiment in the search for saturation effects is the Electron-Ion Collider (EIC), which will be built in the USA. Despite some attempts, the existence of gluon saturation has not been proven, although some of its features may be found in experimental data.

The project aims at creating new theoretical tools for high-precision calculations sensitive to the saturation of gluons, which we will be able to compare with the results of experiments. These methods must involve a description of processes with elementary particles confined by strong interactions (quarks, gluons), as well as a description of the hadrons at high energies. To achieve that, the team will expand the latest methods of quantum field theory, as well as some existing methods not yet used for gluon saturation. However, the aim of the project is not only to create theoretical formalism, but also to implement it in the form of a computer program enabling the calculation of observable effects of gluon saturation in the LHC and EIC colliders. Such calculations are necessary to discover this fascinating state of matter.

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SONATA BIS is a funding opportunity addressed to researchers holding a doctoral degree who want to establish a new research team and become independent research leaders. The 14^th edition was intended for researchers who obtained a doctoral degree from 1 January 2012 to 31 December 2019. To participate, they had to demonstrate at least one published or accepted paper and, in the case of scientific activities in the field of creativity and art, at least one published or accepted work or at least one artistic or artistic-scientific achievement.

There were 417 applications submitted, and the grants were allocated to 63 scientists. The total budget amounts to nearly PLN 206 million.