ELEMENTARY PARTICLE PHENOMENOLOGY

Degree course: 
Corso di Second cycle degree in PHYSICS
Academic year when starting the degree: 
2019/2020
Year: 
1
Academic year in which the course will be held: 
2019/2020
Course type: 
Compulsory subjects, characteristic of the class
Credits: 
6
Period: 
First Semester
Standard lectures hours: 
48
Detail of lecture’s hours: 
Lesson (48 hours)
Requirements: 

Nuclear and subnuclear physics with exercise classes
Quantum physics (Modules 1 and 2)
Electromagnetism (Modules 1 and 2)

Final Examination: 
Orale

The course examination takes the form of a single final oral test. In order to ascertain the expositional abilities in elementary particle physics phenomenology and the level of understanding of the subject, students are asked to make a previously prepared oral presentation. During and after the presentation, questions are asked to test the ability to reason on the subject under examination and to check the understanding of the various topics touched upon during the lessons as well as the analytical and computational skills.

Assessment: 
Voto Finale

The purpose of the course is to provide students with an introduction to the phenomenology of elementary particle physics, defined as the interaction between the two main spheres of activity: on the one hand, the development of the theory that describes the physical world at the subnuclear level and, on the other, the experimental work aimed at verifying the validity of this description and at discovering possible new, as yet unknown and often unexpected aspects. Students will thus acquire a knowledge of the state of the art of both theoretical and experimental elementary particle physics, together with an understanding of the mechanisms and motivations that led us to the current theoretical and experimental scheme. They will also acquire the necessary skills to analyse fundamental interactions both from the point of view of conservation and symmetry laws and with regard to kinematics and the underlying dynamics.

• Symmetries
 > parity violation in weak interactions
 > the V–A formulation of weak currents
 > Cabibbo's theory
 > the GIM mechanism and the CKM matrix
 > CP violation in the Standard Model

• Hadronic Physics
 > Gell-Mann's theory - SU(3)
 > the strong interaction - QCD
 > DIS and ep machines
 > Feynman's quark–parton model
 > asymptotic freedom
 > the "new" particles

• Cosmic Rays and First Discovery
 > e+e– machines
 > discovery of the c and b quarks
 > discovery of the tau lepton
 > pp machines
 > discovery of W±, Z0 and the t quark

• Elementary Particles and Fundamental Forces
 > the spontaneous breaking of symmetries (Higgs)
 > B-meson physics
 > the discovery and measurement of CP violation
 > proton decay
 > the standard model

• General Issues
 > neutrino oscillation and mixing
 > GUT
 > SuSy
 > beyond the 4 dimensions
 > beyond the Standard Model

The first part of the course examines the question of symmetries.
Parity violation in weak interactions through its effect in nuclear beta-decay is discussed in detail, leading to the V–A formulation of weak currents and also Cabibbo's theory. The consequent problem of the non-observation of certain neutral-kaon decays is shown to lead to the GIM mechanism and the prediction of the c-quark, while the requirement that CP be violated is shown to lead to the formulation of the CKM matrix.

The section on hadronic physics deals separately with the two approaches to the sub-structure of the nucleons: Gell-Mann's quark theory and Feynman's parton model. The subsequent unification of the two approaches is then developed through the invention of quantum chromodynamics (QCD). In particular, the description afforded of deeply inelastic electron-proton scattering is presented in detail. The notions of asymptotic freedom and confinement within the quark-parton model complete the description of the strong interaction.

We then move on to cosmic rays and first discoveries of new particles. The natural progression then continues with the early e+e– machines and the discovery of the c and b quarks, followed by the tau lepton. Finally, the remaining discoveries of the W± and Z° bosons and the t-quark at proton-proton machines are described.

Having examined the individual interactions (the weak and strong nuclear forces) we present the unified picture, such as it is, of the elementary particles and fundamental forces that describe their interactions. The path to the Standard Model (SM) of elementary particle physics via the spontaneous breaking of symmetries (the Higgs mechanism) is traced to the present description of the electro-weak interaction. Various related topics, such as B-meson physics, the discovery and measurement of CP violation, proton decay and the implications of Standard Model in general are briefly discussed.

To conclude we examine some new and/or unexplained aspects of modern particle physics. The topics touche upon include: neutrino oscillation and mixing, GUT, SuSy, beyond the 4 dimensions and beyond the Standard Model.

Notes available online:
http://scienze-como.uninsubria.it/phil/Corsi/

Suggested supplementary but not compulsory texts:
P.G. Ratcliffe "An Introduction to Elementary Particle Phenomenology" (IoP, 2014);
D. Perkins, "Introduction to High Energy Physics" (CUP, 2000);
F. Halzen & A. Martin, "Quarks and Leptons" (Wiley, 1984);
Povh et al., "Particles and Nuclei" (Springer, 1995).

Conventional blackboard lectures, including exercise classes in the classroom for a total of 48 hours.

Office hours:
by appointment (write to philip.ratcliffe@uninsubria.it)