# PHYSICS OF ELEMENTARY PARTICLES

**PHYSICS 9012 (coorte 2018/2019)**- NUCLEAR AND PARTICLE PHYSICS AND ASTROPHYSICS 2 61847
- THEORETICAL PHYSICS 61842
- MATHEMATICAL METHODS IN PHYSICS 61843
- MATTER PHYSICS 2 61844

**PHYSICS 9012 (coorte 2019/2020)**- NUCLEAR AND PARTICLE PHYSICS AND ASTROPHYSICS 2 61847
- THEORETICAL PHYSICS 61842
- MATHEMATICAL METHODS IN PHYSICS 61843
- MATTER PHYSICS 2 61844

OVERVIEW

The course aims to deepen some of the topics that are at the heart of modern research in particle physics.

## AIMS AND CONTENT

LEARNING OUTCOMES

The aim of the course is to present the basic analytical tools and the phenomenological bases of modern particle physics, through various examples and applications.

AIMS AND LEARNING OUTCOMES

- introducing basic tools to understand modern particle physics and the necessary pre-requisite to achieve an understanding of particle physics based on quantum mechanics and relativity
- introducing modern particle physics from a phenomenological viewpoint
- introducing to techniques and methods to study elementary particles’ properties and their interactions, with particular focus on the theory and phenomenology of strong interactions.
- discussing open problems in high-energy physics
- all topics are complemented by examples and applications

Teaching methods

Blackboard lectures accompanied by examples and exercises. For some presentations on phenomenological topics slides will also be used.

SYLLABUS/CONTENT

The course syllabus is divided into two parts of approximately 24 hours each:

**PART A**: The instruments of particle physics (Alessandro Petrolini).

- Review of the Standard Model.
- Complements of Quantum Mechanics. Examples and Applications.
- Complements of Relativistic Mechanics. Lorentz invariance. Relativistic kinematics. Examples and Applications.
- Decays, Scattering and matrix S. Momentum and helicity eigenstate. Decay width and cross section. Phase space. Outline of perturbative methods and Feynman diagrams. Examples and Applications.
- Symmetries. Continuous symmetries. Discrete symmetries. Symmetries and scattering amplitudes. Examples and Applications.
- The properties of the particles and their determination. Conservation Laws. Partial Wave analysis. Examples and Applications.

**PART B**: Phenomenology of strong interactions (Simone Marzani).

- Review of hadronic physics and the quark model. Review of the parton model.
- Quantum electrodynamics (QED) as a gauge theory. Perturbation theory and Feynman rules.
- Quantum chromodynamics (QCD) as a non-Abelian gauge theory. Feynman rules. Similarities and differences with QED.
- Properties of QCD: asymptotic freedom and confinement. The running coupling constant.
- Study of strong interactions in electron-positron collisions. Inclusive cross-section and R ratio.
- Introduction to the concept of jets and event shapes. Measurements of the strong coupling constant.
- Study of strong interactions in electron-proton collisions. The parton model in the light of QCD. Radiative corrections and DGLAP equations.
- Introduction to the study of strong interactions with hadronic colliders.

RECOMMENDED READING/BIBLIOGRAPHY

- Thomson:
*Modern Particle Physics*, Cambridge University Press - Halzen, Martin:
*Quarks and Leptons,*Wiley - Ellis, Stirling, Webber:
*QCD and Collider Physics*, Cambridge University Press

## TEACHERS AND EXAM BOARD

**Ricevimento:** Please fix an appointment by e-mail.

Exam Board

ALESSANDRO PETROLINI (President)

SIMONE MARZANI (President)

GIOVANNI RIDOLFI

MARCO PALLAVICINI

CARLA BIGGIO

## LESSONS

Teaching methods

Blackboard lectures accompanied by examples and exercises. For some presentations on phenomenological topics slides will also be used.

## EXAMS

Exam description

Written test with exercises aimed at verifying the concepts of the first part of the course. The oral exam instead consists of a discussion of the written test and an interview aimed at verifying the topics covered in the second part of the course.

Assessment methods

The written exam contains exercises both of a theoretical nature, aimed at verifying the comprehension of the arguments developed in class, and of applicative nature. In the latter case, the resolution of numerical problems aims to verify that the student is familiar with the concepts discussed in class and he/she can apply them to solve physical problems. The oral exam, of a duration of about 30 minutes, instead consists essentially in the exposition of one of the topics addressed during the study of strong interactions.