Structure of nuclear matter

Irfu conducts fundamental research, mainly experimental but also theoretical, on nucleons and nuclei, elementary bricks of matter whose cohesion is ensured by strong interaction.

Strong interaction occurs at two successive scales. The first is the assembly of quarks and gluons, whether deconfined in plasma or bound in the nucleon and other hadrons. The second concerns the nucleon assemblies which constitute the nuclei of the different atoms. Irfu's objective is to deepen our knowledge of these systems, as well as to discover extreme states of nuclear matter:

Structure of nuclear matter

Top: Phase diagram (nuclear density, temperature) of nuclear matter. Bottom: Table of nuclei.

Last update : 06/08 2018 (545)

Research themes
The structural aspect of the atomic nucleus is governed by the interaction between nucleons, protons and neutrons, binded by the strong interaction. This multibody quantum system is often described by a nuclear medium field built on an effective nucleon-nucleon interaction. This interaction became increasingly sophisticated as accurate spectroscopy data accumulated.
The study of nuclear reactions aims at describing the mechanisms sustaining the evolution of nuclear matter when it undergoes a modification of its state. This modification can occur after an external excitation (e.g., neutron capture) or internal excitation (e.g., beta decay). This evolution is the consequence of the dynamics of nucleons in interaction with its neighbours and of the reorganization of the nuclear structure.
The interaction between quarks and gluons is described by the Quantum Chromo-Dynamics (QCD) theory. This strong interaction confines the quarks and gluons inside the protons, neutrons and other hadrons. When a hadron is torn apart, its constituting quarks and gluons, instead of being liberated, will recombine with newly created ones to form new hadrons with different properties.
DPhN is strongly engaged in the study of the partonic structure (in terms of quarks and gluons) of nucleons, protons and neutrons. Nucleons are singular objects as about 90% of their mass originates not from their constituent masses, but rather from the strong interaction they experience. Nucleons are also a benchmark laboratory to study confinement and deconfinement mechanisms which remain an open key point, although QCD is a well established theroy in the standard model.


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