Phenomenology of Elementary Particles


course ID

Lecturer

CFU

6

Length

14 Weeks

Semester DD

Second


Course details

The building blocks of the Standard Model: leptons, quarks, gauge bosons, the Higgs boson. The interactions of the Standard Model: survey of the QED, the strong sector QCD, the electroweak sector SU(2)xU(1), the Higgs mechanism. Scattering and decay processes in perturbation theory: the Dyson series and the Feynman diagrams, the phase-space integrals. The technique of effective field theory: general features of effective theories, symmetries and power-counting, the effective theory of heavy quarks, the effetive theory of low-energy QCD, Fermi’s theory of weak interactions, effective theories as probes of new physics. Charged leptons: the muon decay and the determination of the Fermi constant. Weak interactions of strange particles: leptonic and semileptonic decays of charged kaons and extraction of CKM matrix elements, CP violation in mixing and decays of the neutral kaons. Heavy quarks: heavy quark masses, CP violation in mixing and decays of B mesons, a few words about D meson physics. The Higgs boson: the mass, the self-interaction and the Yukawa couplings with quarks.

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Objectives

LEARNING OUTCOMES
This course aims at providing master students interested in High Energy Theoretical Physics
with the tools needed to understand our theoretical description of the basic physical processes involving elementary particles that are subjected to electromagnetic, weak and strong nuclear interactions, as well as to discuss current evidence for new physics beyond the Standard Model.

The course is taught by lectures. Discussions and digressions on specific topics triggered by
questions from the students are expected and highly welcome. The lectures will be tuned on the average preparation level of the students about elementary particle physics processes and quantum field theory.

KNOWLEDGE AND UNDERSTANDING:
The course should allow the students to extend and deepen their knowledge in Theoretical Physics with the goal of understanding how a theoretical model can describe experimentally observed (or observable) phenomena involving elementary particles that are subjected to electromagnetic, weak and strong nuclear interactions.

APPLYING KNOWLEDGE AND UNDERSTANDING:
Students are expected to become able to study in a quantitative way, following also advanced books and scientific review articles, a few simple key processes (e.g. decays, scattering and resonances) in elementary particle physics.

MAKING JUDGEMENTS:
Students should be able to critically analyse the current level of understanding of elementary
particle physics phenomena, for instance whether the description of a certain process is from first principles or merely phenomenological. To this goal they should get familiar with the effective theory approach and master the relation of effective models to (relatively more)
fundamental theories.

COMMUNICATION SKILLS:
Students must be able to discuss a certain process involving elementary particles in a clear
and technically appropriate language, disentangling the pieces of experimental info from the
the theoretical ideas used for the phenomenological description and stressing possible weak
point in the current theoretical understanding.

LEARNING SKILLS:
Students are expected to understand the key role played by elementary particle phenomenology in the development of High Energy Physics in the last 60 years (or so), which implied a crucial cross-fertilization between theoretical ideas and experimental data, as well as to be able to employ the research methods and the pieces of technical info they learned in their subsequent activities both for the master thesis and possibly as young researchers.