CODE  62422 

ACADEMIC YEAR  2022/2023 
CREDITS 

SCIENTIFIC DISCIPLINARY SECTOR  FIS/02 
TEACHING LOCATION 

SEMESTER  1° Semester 
PREREQUISITES 
Prerequisites
You can take the exam for this unit if you passed the following exam(s):

TEACHING MATERIALS  AULAWEB 
The aim of the course is to introduce the student to the physics of relativistic processes and in particular to the Standard Model of the Electroweak Interactions. To this end, we will first provide the necessary notions of quantum field theory that will first lead to the study of Quantum Electrodynamics and then move on to nonAbelian gauge theories and, in fact, to the Standard Model of Electroweak Interactions.
Introduction to relativistic processes and construction of the Standard Model of Electroweak Interactions.
The student will learn how to formally construct the Standard Model of the Electroweak Interactions and its phenomenological consequences. To this end he/she will first be given the necessary field theory tools to learn the basics of Quantum Electrodynamics first, then the YangMills theories and finally the spontaneous symmetry breaking, in order to arrive at the complete construction of the Standard Model. Then, thanks to the acquired calculation techniques, the student will be able to calculate different processes (decay amplitudes and cross sections) at the first order in perturbation theory. In the last lessons we will focus on the problem of neutrino masses and we will analyze various possibilities of extending the standard model to include them. Finally we will briefly mention the problems of this model and the directions in which it is possible to extend it to solve them.
The contents of the compulsory courses, in particular the course in theoretical physics.
If permitted by the measures to contain the pandemic Covid19, I will make blackboard lectures, maybe supported by telematic trasmission via Teams or in other ways communicated before the beginning of the course.
Field theory recalls. Scalar fields: recalls, scalar propagator. Review of scattering theory, matrix S. The method of Feynman diagrams. Feynman rules for the scalars. Decay amplitudes and cross sections. Spinorial fields: recalls, second quantization, fermionic propagator. Feynman rules for fermions. Quantum electrodynamics: gaugefixing and quantization of the electromagnetic field, coupling with matter. Feynman rules for quantum electrodynamics. Calculations of amplitudes and traces of gamma matrices. Calculation of cross section for scattering Compton and e+ e in mu+ mu. NonAbelian gauge theories: properties, Lie algebras, SU(2), SU(3), SU(N). The birth of the Standard Model: SU(2), SU(2) xU(1). Goldstone's theorem. The BroutEnglertHiggs mechanism: Abelian case and nonAbelian case. The Lagrangian of the Standard Model: bosonic part, fermionic part without fermion masses, Yukawa terms. The Lagrangian in the massbasis and the origin of the CKM mixing. Calculation of the decay amplitude of the muon, the Z, the Higgs boson and the neutrinoelectron scattering. Derivation of Fermi Lagrangian. Accidental symmetries of the standard model. Masses of neutrinos and seesaw models. Introduction to physics beyond the standard model.
Carlo M. Becchi and Giovanni Ridolfi, "An introduction to relativistic processes and the standard model of electroweak interactions", Springer
Michael E. Peskin and Daniel. V. Schroeder, "An introduction to Quantum Field Theory", Perseus book
F. Mandl and G. Shaw, "Quantum field theory", John Wiley and sons
TaPei Cheng and LingFong Li, "Gauge Theory of Elementary Particle Physics", Oxford Science Publications
Office hours: Every day, by appointment via email.
Office hours: The students may contact the teacher at any time, for discussions, clarifications of the lectures, suggestions for the solution of problems. A preliminary contact via email is suggested.
CARLA BIGGIO (President)
SIMONE MARZANI
MARCO PALLAVICINI
ALESSANDRO PETROLINI
GIOVANNI RIDOLFI (President Substitute)
The course is in the first semester of the second year of the Laurea Magistrale.
Lessons normally start at the end of September.
All class schedules are posted on the EasyAcademy portal.
Written and oral exam.
In the written test we want to ascertain that the student has acquired the computational techniques of quantum field theory and that he can therefore calculate simple cross sections or decay amplitudes in processes of the standard model of the electroweak interactions, at the first order in perturbations theory. In the oral examination it is verified that the student has learned the fundamental concepts taught in the course such as, for example, gauge theories, spontaneous symmetry breaking and in particular the fundamental characteristics of the standard model of the electroweak interactions.