NUCLEAR REACTION THEORY

The course aims to provide the basic elements of scattering theory applied to collisions between nucleons and to nuclear reactions. We also want to introduce the student to the treatment and phenomenology of heavy ion reactions at intermediate energies, from fusion and deep-inelastic reactions to the liquid-gas phase transition in nuclear matter. The approach followed is theoretical-phenomenological.

Knowledge and understanding.

Critical understanding of the most advanced developments of Modern Physics, both theoretical and experimental, and their interrelations, also across different subjects. Remarkable acquaintance with the scientific method, understanding of nature, and of the research in Physics. During the course the student will understand the main nuclear reaction mechanisms, from low to intermediate energies, framing them in the current context of research in nuclear physics, and will acquire the main theoretical tools for the description of such processes.

Applying knowledge and understanding.

Ability to identify the essential elements in a phenomenon (concerning nuclear reactions and the behavior of nuclear matter), in terms of orders of magnitude and approximation level, and being able to perform the required approximations. Ability to use analogy as a tool to apply known solutions to new problems, related to the description of new nuclear processes of present interest (problem solving).

Communication skills.

Ability to discuss about advanced physical concepts, both in Italian and in English. These skills will be developed in the context of the communication of issues related to the dynamics of nuclear reactions and the properties of nuclear matter.

Learning skills.

Ability to acquire adequate tools for the continuous update of one's knowledge. Ability to access to specialized literature both in the specific field of nuclear reactions, and in closely related fields.

The course includes lectures (5 CFU = 35 hours), mainly on the blackboard, and some hours of classroom exercises (1 CFU = 15 hours), with student involvement.

SCATTERING THEORY AND NUCLEAR REACTIONS - Elastic and inelastic reactions. Kinematics of nuclear reactions. Classical scattering theory. Qualitative characteristics of nuclear reactions. Quantum scattering theory. Description in partial waves: phase shifts and interference. Hard-Sphere Scattering. Low energy scattering. Bound states and scattering resonances. Scattering length, effective range and nuclear interaction. Born approximation for elastic and inelastic reactions. Double potential model and Born approximation in distorted waves (DWBA). Direct reactions: stripping, pick-up and knock-out. Description of the pick-up reaction (p, d). Impulse approximation. Eikonal approximation. Charge exchange reactions and connections with beta decay. Compound nucleus reactions. Empirical theory of optical potentials.

NUCLEAR COLLISIONS AT INTERMEDIATE ENERGY - Nuclear matter Equation of State (EoS). Isospin and symmetry energy. Nuclear dynamics in phase space. Wigner's transform and its properties. Semi-classical approximation. Boltzmann-Nordheim-Vlasov transport equation. Zero and First sound in nuclear matters. From incomplete fusion to multifragmentation: the spinodal mechanism for the dynamics of liquid-gas transition in nuclear matter. Deep-inelastic reactions and neck formation mechanism. Some notions about collective, radial, transverse and elliptic flows in heavy ion reactions.

1) J.J. Sakurai, Meccanica Quantistica Moderna, Ed. Zanichelli, 1990 - Capitolo 7

2) G.R. Satchler, Introduction to Nuclear Reaction, Macmillian Education, 1990

3) C.A. Bertulani, P. Danielewicz, Introduction to Nuclear Reactions, IOP Publishing, London, 2004