Nuclear physics is one of the fundamental areas of science which, through its present technological and computational advances, continues to open new frontiers of discovery and continues to address the most basic questions about the physical universe and its origin.
Indeed, 99.9 percent of the mass of all the atoms in the universe originates from the nuclei at their centres, the volumes of which are over trillion times smaller than the atoms themselves. Even though nuclei are incredibly tiny and dense, they are complex structures made of protons and neutrons. In turn, protons and neutrons have an underlying structure of quarks, which are bound by the strong interaction mediated by the force-carrying gluons. This complexity results in countless possible states of nuclei and of nuclear matter, described by different spin or isospin numbers, temperatures and densities. One of the greatest challenges in nuclear physics is to understand the structure of nuclei, and of their constituent protons and neutrons, emerging from such complexity. The scientific activity of the Division of Nuclear Physics and Strong Interactions embraces all these topics. Research in experimental and theoretical areas of nuclear physics and strong interactions is carried out in three departments of this Division: in the Department of the Structure of Atomic Nucleus, in the Department of Strong Interactions and Mechanism of Nuclear Reactions, and in the Department of Ultrarelativistic Nuclear Physics and Hadron Structure.
The main questions guiding nuclear structure research can be viewed from two general and complementary perspectives: the microscopic perspective, focusing on the motion of individual nucleons moving in a mean field potential created by all the nucleons, which gives rise to the quantum shell structure, and the mesoscopic perspective which focuses on the highly organized complex system exhibiting certain symmetries, regularities, and collective behaviour. In spite of this duality, the two characteristics seem to be intimately related. Presently, one of the major challenges is to investigate and understand how to bridge the gap between these two approaches. It is commonly accepted that in order to gain a more profound understanding of nuclear structure, experimental and theoretical efforts should focus on nuclei localised in the unexplored regions of the nuclear landscape, in terms of their isospin, spin or temperature. Experimental studies of nuclear structure in various regions of the nuclear chart are carried out in the Department of the Structure of Atomic Nucleus by performing experiments with radioactive and stable beams.
Studies of the strong force and of the constituents that make up the internal structure of the proton and the neutron,
quarks and gluons, are guided by a few basic questions:
a) How do the internal structural properties of protons and neutrons arise from the behaviour of their constituents?
b) How are those properties reflected in the structure of complex nuclei?
c) Can QCD establish a link between interacting nucleons and the underlying structure of quarks and gluons?
In order to elucidate the above issues, experimental and theoretical investigations are conducted in the Department of Strong Interactions and Mechanism of Nuclear Reactions.
With the advent of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), it became possible to create the state of matter which existed a few microseconds after the Big Bang, when the temperature of the universe was several trillion degrees. The properties of such matter can only be investigated in the laboratory, as this information is inaccessible by any conceivable astronomical observations made with telescopes and satellites. Along these lines of research, in the Department of Ultrarelativistic Nuclear Physics and Hadron Structure hadronic and nuclear reactions at relativistic energies are studied within the LHC-ALICE experiment.
Recently, a new proton cyclotron Proteus-235 was installed at the Cyclotron Center Bronowice located on the premises of IFJ PAN.
The Division of Nuclear Physics and Strong Interactions carries out a research program in the domain of nuclear physics by employing this cyclotron.
Studies are aimed at the two current topics of nuclear science: a) dynamics of a few-nucleon systems and physics of nuclear clusters, and b) collective,
high-energy excitations in nuclei (e.g., giant nuclear resonances) in the yet unexplored regions of excitation energy and spin. Experimental equipment
is based on modern detector systems such as:
a) Big Instrument for Nuclear reaction Analysis (BINA) – it is used for measuring light charged particle energy and angle correlations,
b) a multidetector setup of scintillator detectors HECTOR and a new generation scintillator detector system PARIS,
c) charged particle multidetector array KRATTA,
d) germanium detectors setup.
The energy of the proton beam which ranges from 70 MeV to 230 MeV and a possibility of quick alternation between different beam energies makes the CCB laboratory an attractive and unique place in Europe for a certain class of nuclear physics experiments.