###
Objectives

The aim of the course is to learn the experimental evidences and the

methodologies that led to the formulation of the Standard Model (SM) of

elementary particle physics, from the beginning of the discipline in the

30s and 40s of the last century until the formulation of the SM. The

course is closely linked to the theoretical courses of the first

semester and to the annual course of Laboratory.

At the end of the course the students have to:

1) know and be able to discuss the fundamental concepts of the SM

2) know the fundamental experiments that allowed the development of the SM

3) to have understood the main methodologies of the experimental

particle physics, both the technological and the statistical aspects.

### Channels

### PAOLO BAGNAIA Teacher profile

#### Programme

Introduction.

1. The static quark model – Hadron characteristics – The eightfold way – Omega minus discovery – The static quark model – Meson and baryon quantum numbers – Group theory – Group properties – Symmetry groups – Abelian groups – Lie groups – Algebras – Representations – SU(2) – SU(3) – Applications to elementary particle physics.

2. The hadron structure – Elastic scattering – Inelastic scattering e-Nucleus – Mott formula – Nuclear form factors – Elastic and inelastic scattering e-nucleon – Kinematics – Rosenbluth formula – Deep inelastic scattering – The SLAC experiment – Structure functions – Bjorken scaling – The parton model – The quark–parton model – Sum rules – Scaling violations.

3. Heavy flavors – The Mandelstam variables – Discovery of the J particle – The reaction e+e– to leptons and hadrons – Discovery of the J/psi particle – Charmonium – Open charm – The third family : the tau lepton and the b quark – The t quark.

4. Weak interactions – Introduction to the weak interactions : charged and neutral currents – The Fermi theory – The coupling constant GFermi – Lepton universality – Parity violation – The nu helicity – Weak decays of mesons and leptons – Weak decays and symmetries – Fermi and Gamow–Teller transition – Beta decays – Cabibbo theory – GIM mechanism.

5. The K0 meson – K0 oscillations – Discovery of the K0L decay – K0 oscillations – K0 regeneration – CP violation (direct and indirect) – The CPT theorem.

6. High energy neutrino interactions – The neutrino beams – Wide- and narrow-band beams – Neutrino detectors – Heavy liquid bubble chambers – Emulsions – Calorimeters (CDHS, CHARM) – Charged currents – Thresholds – Helicity constraints – Cross sections – Structure functions – Sum rules – Comparison with ep – Neutral currents – Couplings – Cross sections (total and differential) – Leptonic and semi-leptonic processes – Measurement of the Weinberg angle.

#### Adopted texts

a copy of the slides in http://www.roma1.infn.it/people/bagnaia/particle_physics.html

Each set of slides contains the general textbooks of reference. Here some general textbooks are listed, for the convenience of the students:

R.Cahn, G.Goldhaber – The experimental foundation of particle physics [a collection of original papers + explanation, the main source for the exam];

W. E. Burcham - M. Jobes – Nuclear and Particle Physics – John Wiley & Sons [clear and complete, but quite old]

Yorikiyo Nagashima – Elementary Particle Physics – Wiley VCH – 3 vol. [clear, complete, but difficult and expensive]

A.Bettini - Introduction to Elementary Particle Physics [brilliant, useful as a complement]

D.Perkins - Introduction to High Energy Physics, 4th ed. [ditto];

B.R.Martin, G.Shaw – Particle Physics [interesting, some arguments missing];

Povh, Rith, Scholz, Zetsche - Particles and Nuclei [ditto, simpler];

M. Thomson – Modern Particle Physics [ditto];

C.Dionisi, E.Longo - Fisica Nucleare e Subnucleare 1 [reference for "prerequisiti"]

L.Maiani - O.Benhar – Meccanica Quantistica Relativistica [also translated in English, reference for theory];

L.Maiani – Interazioni elettrodeboli [ditto];

The Review of Particle Physics [professional, useful as a reference, but definitely NOT a textbook]

#### Bibliography

(see previous table)

#### Prerequisites

An introductory course FIS/04 the three-year degree (or equivalent preparation), containing the basic concepts of nuclear physics and of the particles and detectors used. The background includes the classification of particles (leptons, neutrinos, hadrons, quarks), the basic principles of dynamics (cross section, matrix element, phase space, energy loss in the crossing of a medium) and the main detectors (chambers, scintillators, calorimeters, Cerenkov counters).

#### Study modes

Standard: class lectures. Encouraging students to ask questions. Some seminars on topical subjects and on the research carried out in the department and the possibility of thesis.

#### Exam modes

The student is allowed to propose a particular subject to start her/his exam. Then the discussion and the next questions can cover the entire exam program. The exam consists of an interview on the most relevant topics presented during the course. To pass the exam, the student must be able to present a topic or repeat a calculation. Students will be asked to apply the methods learned during the course. The evaluation takes into account:

- correctness and completeness of the presented concepts;

- clarity and rigorous visualization;

- analytical development of the theory;

- attitude in problem solving (method and results).

Exam reservation date start | Exam reservation date end | Exam date |
---|---|---|

30/12/2021 | 13/01/2022 | 17/01/2022 |

01/02/2022 | 10/02/2022 | 14/02/2022 |

07/04/2022 | 25/04/2022 | 02/05/2022 |

30/05/2022 | 20/06/2022 | 27/06/2022 |

13/06/2022 | 04/07/2022 | 11/07/2022 |

30/07/2022 | 28/08/2022 | 05/09/2022 |

23/09/2022 | 27/10/2022 | 01/11/2022 |

- Academic year: 2021/2022
- Curriculum: Particle and Astroparticle Physics (Percorso valido anche fini del conseguimento del titolo multiplo italo-francese-svedese-ungherese) - in lingua inglese
- Year: First year
- Semester: Second semester
- SSD: FIS/04
- CFU: 6

- Attività formative caratterizzanti
- Ambito disciplinare: Microfisico e della struttura della materia
- Exercise (Hours): 36
- Lecture (Hours): 24
- CFU: 6
- SSD: FIS/04