B1046 - GRANDI CONQUISTE E TRAGUARDI DELLA FISICA DELLE PARTICELLE

Learning outcomes

At the end of the course, the student will have a general knowledge of the path that gave rise to modern particle physics, of the main experimental results that have characterized its evolution and of the most important technological implications that such research has had on contemporary society. He/she will also learn about the state of the art of frontier research and the main directions towards which the scientific community is moving to resolve the most important questions of fundamental physics that are still open.

Course contents

Module 3A: Basic tools and concepts (8 hours)

• Overview of the Standard Model of fundamental interactions
• Open questions in elementary particle physics
• Principal fields of experimental particle physics (dark matter, neutrinos, collider experiments)
• Cross-sections and particle production rates
• Luminosity and integrated luminosity Collider
• Luminosity and application to the Large Hadron Collider (LHC)
• Radiation–matter interaction: general concepts
• Ionization and energy loss in matter
• Bethe–Bloch formula
• Multiple scattering of charged particles
• Synchrotron radiation
• Energy loss via bremsstrahlung
• Electromagnetic showers
• Hadronic showers
• Shower modeling in detectors
• General principles of particle detection methods
• Particle detectors: trackers, calorimeters, and particle identification detectors
• Track reconstruction in particle detectors
• Momentum measurement via track curvature and sagitta
• Resolution in momentum measurement and experimental contributions
• Effects of multiple scattering on tracker precision

Module 3B: Recent experimental measurements (8 hours)

The Higgs boson

• Higgs boson production in collider experiments
• Higgs boson decay channels
• Measurement of the Higgs boson mass
• Determination of production and decay rates
• Comparison of measurements with Standard Model predictions

The top quark

• Top quark production in collider experiments
• Decay channels and experimental signatures of the top quark
• Measurement of the top quark mass
• Role of the top quark in precision tests of the Standard Model

Flavor physics

• Decays of mesons containing heavy quarks
• CP violation and asymmetry measurements
• Rare decays as indirect tests of new physics
• Experimental strategies for precision measurements in the flavor sector

Neutrinos and dark matter

• Experimental evidence for the existence of massive neutrinos
• Neutrino oscillations and measurable physical parameters
• Experimental evidence for the existence of dark matter
• Experimental strategies for dark matter searches
• Interpretation of experimental limits and comparison with theoretical models

Module 2: Great achievements in particle physics (16 hours)

• Great achievements of the Standard Model
• Distinction of particles, quantum numbers, units of measurement in particle physics
• Strangeness and the s quark
• Discovery of the K meson and the Lambda baryon. Quark model and SU(3)-flavor symmetry.
• Charm and the c quark. Discovery of the J/psi particle. SU(4)-flavor symmetry Leptons and discovery of the tau lepton
• Beauty and the b quark.
• Discovery of the Y particle. Color and SU(3)-color symmetry. Gauge symmetry and QED. Evidence of jets and discovery of the gluon Running of QED and QCD couplings
• Asymptotic freedom of QCD
• Evidence of quark color. Weak interactions
• Discovery of the W+- and Z0 bosons Top and the t quar
• Discovery of the top. Discovery of the tau neutrino
• Deep Inelastic Scattering (DIS) and first evidence of quarks
• Parton model, scaling and scaling violations in QCD, structure functions
• Evidence of P violation and CP violation in weak processes Helicity and chirality
• Weak charged current (CC) and neutral current (NC) processes
• Cabibbo angle and introduction to quark mixing Quark-Gluon Plasma (QGP)
• Characteristics and properties
• Experimental evidence in ultra-high energy heavy-ion collisions

Module 1: Technological developments in the evolution of particle physics experiments (16 hours)

CMOS Technology

• Technological principles for microchip fabrication on silicon wafers, technology nodes
• Shared production via Multi-Project Wafers (MPW) and Engineering RUNs for research purposes
• Effects of ionizing particles on MOS transistors and CMOS technologies
• Single Event Effect (SEE) and Total Ionizing Dose (TID)
• Radiation-hardening techniques, annealing, Triple Modular Redundancy (TMR) for electronics in radiation environments
• Overview of modern programmable electronics, from microprocessors to FPGAs and GPUs

Coaxial Cables and Optical Fibers

• Use of coaxial cables in past and present physics experiments
• Principles of signal propagation on metallic cables, transmission lines
• Concepts of Characteristic Impedance and Propagation Constant
• Fundamentals of antenna operating principles
• Use of optical fibers in data acquisition systems for physics experiments
• Total internal reflection, optical windows, single-mode and multi-mode fibers
• Comparison between coaxial cables and optical fibers in physics experiments

Photomultiplier Tubes (PMT) and Silicon Photomultipliers (SiPM)

• Use of PMTs in past and present experiments
• Primary and secondary photoemission, dark current
• Scintillation and Cherenkov light
• Modern large-volume experiments for neutrino detection
• The transition from PMTs to solid-state Silicon Photomultipliers (SiPM)
• Characterization of SiPMs, insensitivity to magnetic fields
• Comparison between PMTs and SiPMs

Trigger and Data Acquisition (DAQ) systems in large-scale high-energy physics experiments

• Optical fiber-based DAQ for large-scale detectors
• Trigger systems, continuous acquisition, and the data management problem
• Tree networks for data distribution in large-scale global physics experiments, the Tier-0, Tier-1, and Tier-2 systems
• Activities in Bologna and in Italy

Readings/Bibliography

A. Bettini, Introduction to Elementary Particle Physics, Cambridge University Press, 2014

Lecture notes

Teaching methods

Frontal lessons. Part of the lessons is dedicated to the discussion of questions and exercises

Assessment methods

The assessment will focus on in-depth analysis and discussion of topics included in the course programme.
The oral exam will begin with the candidate presenting a topic of their choice for each of the three modules of the course.
The oral exam will then continue with questions or requests for clarification from the committee on topics related to the chosen subjects.
Overall, the assessment will consist of 3 or 4 questions, including the topics of choice. Only if the candidate answers all questions exhaustively will the assessment be 30 or 30L. Otherwise, 1 to 4 points will be deducted for each question answered incompletely.

Students with DSA or temporary or permanent disabilities: it is recommended to contact the responsible University office in good time (https://site.unibo.it/studenti-con-disabilita-e-dsa/it): it will be the office's responsibility to propose any adaptations to the interested students, which must however be submitted, with a 15-day notice, to the approval of the professor, who will evaluate the opportunity also in relation to the educational objectives of the course.

Teaching tools

Slides presented in class and notes on Virtuale

Office hours

See the website of Alessandro Gabrielli

See the website of Luisa Cifarelli

See the website of Angelo Carbone