80327 - Nuclear and Subnuclear Physics

Learning outcomes

At the end of the course, the student has a basic knowledge of Nuclear and Subnuclear Physics. In particular, the student is introduced to the physics of the atomic nucleus and constituents of the standard model of elementary particles.

Course contents

Part 1

Special relativity, symmetries and group theory
Lorentz transformations and Minkowski spacetime. Causal structure. Tensors and transformations of the electromagnetic field. Maxwell equations in covariant form.

Action principle, global and local symmetries, Noether's theorems. Group theory: definitions and examples. U (1), SO (N), SU (N).  Representations. Lie algebras.

Relativistic mechanics, relativistic definitions of energy and momentum, quadrimomentum. Particle decay. Scattering processes and Mandelstam variables. Relativistic wave equations: Klein-Gordon equation, Yukawa potential, introduction to gauge theories.

 

Part 2

Nuclear physics
Units of measurement in nuclear and subnuclear physics. The study of microscopic systems, cross section. Properties of microscopic particles. Kirchhoff's theory of diffraction. Calculation of cross sections, differential cross sections, absorption sections, optical theorem, diffraction of an absorbent circular disk.

The nucleus and its constituents. The nuclear radius, differential cross section of neutrons on nuclei.
Nuclear binding energy, the concept of binding energy, experimental data. Liquid drop model, volume, surface, coulomb, asymmetry and pairing terms, Weizsacker formula.
Review of quantum mechanics, wave function, energy and momentum, orbital angular momentum and spin, sum of angular moments. Identical particles, symmetry and antisymmetry of wave function, spin-statistic theorem.
The nucleus as fermion gas, counting the quantum-mechanical states of a microscopic particle in a volume, the expression of the nuclear binding energy.

The nuclear shell model, nuclear potential, separation energies, Saxon-Wood potential, spin-orbit interaction in electromagnetism, spin-orbit interaction in strong nucleon interaction, comparison with experimental data.

Physics of the elemental particles

A look at the standard model, the concept of particle, particles antiparticles and flavor quantum numbers, quark leptons and hadrons, weak strong and electromagnetic interactions, the parameters of the standard model.

Estimate of relative intensity of interactions. A hint to the quantized field concept, the description of the interactions, the case of electromagnetic interaction, real and virtual quanta, two-vertex processes in QED, higher order processes, some experimental tests.

Strong interaction. Color charges and gluons, structure of strong interaction, flavor, isospin, asymptotic freedom and confinement. Flavor quantum numbers. The quark model of the hadrons, the structure of the hadrons, spin masses and electric charges, mesons, baryons and anti-baryons. The quark model of mesons, mesons with light quarks, excited mesonic states, decay patterns. The quark model for baryons, the color charge.

The weak interaction. Beta decay, neutrino, analogy with electrodynamics, antineutrino and W field, diffusion and capture processes, universality of weak interaction. Concept of symmetry in physics. Violation of parity in weak interactions. A hint at the electroweak theory, meaning of parity violation, isospin and weak hypercharge, hint at the Higgs mechanism. A hint at flavor mixing.

Readings/Bibliography

Lecture notes.

Supplementary reading:

M. Gasperini, "Manuale di Relatività Ristretta", Springer.

S. Braibant, G. Giacomelli, M. Spurio: "Particelle e Interazioni Fondamentali", Springer.

A.J. Larkowski.: "Elementary Particle Physics", CUP.

 

Teaching methods

Lectures on blackboard.

Assessment methods

Written and oral exam.

The written exam is divided in two parts, one for each part of the course. The final grade for the written part is obtained by averaging the grade of part 1 with weight 2/5 and the grade of part 2 with weight 3/5. Admission to the oral exam is achieved if the grade is bigger or equal to 18/30.

The oral exam is also divided in two parts. The total final grade is again assigned by averaging with weight 2/5 the final grade in part 1 and weight 3/5 the final grade in part 2.

Office hours

See the website of Fiorenzo Bastianelli

See the website of Nicola Semprini Cesari