HIGH ENERGY NUCLEAR PHYSICS

Apprendere i concetti, le problematiche fisiche e le principali metodologie sperimentali e di analisi nel campo della fisica nucleare di alta energia

In riferimento ai cosiddetti Descrittori di Dublino, questo corso contribuisce a acquisire le seguenti competenze trasversali:

Conoscenza e capacità di comprensione:

• Capacità di ragionamento induttivo e deduttivo.
• Capacità di apprendere e valutare i risultati sperimentali nel campo della fisica nucleare tramite la lettura di articoli specialistici
• Capacità di impostare un problema utilizzando opportune relazioni fra grandezze fisiche (di tipo algebrico, integrale o differenziale) e di risolverlo con metodi analitici o numerici.
• Capacità di effettuare l'analisi statistica dei dati.
• Capacità di effettuare sessioni di analisi di dati reali estratti da esperimenti di fisica nucleare

Capacità di applicare conoscenza:

• Capacità di applicare le conoscenze acquisite per la descrizione dei fenomeni fisici utilizzando con rigore il metodo scientifico.
• Capacità di valutare le performance di esperimenti nel campo della fisica nucleare ed effettuare l'analisi dei dati sperimentali
• Capacità di effettuare calcoli numerici e di simulazione

Autonomia di giudizio:

• Capacità di ragionamento critico.
• Capacità di individuare i metodi più appropriati per analizzare criticamente, interpretare ed elaborare i dati sperimentali.
• Capacità di individuare le previsioni di una teoria o di un modello.
• Capacità di valutare l'accuratezza e l'importanza delle misure esistenti in letteratura
• Capcità di valutare la bontà e i limiti del confronto tra dati sperimentali e modelli teorici

Abilità comunicative:

• Capacità di esporre oralmente, con proprietà di linguaggio e rigore terminologico, un argomento scientifico, illustrandone motivazioni e risultati.
• Capacità di descrivere in forma scritta, con proprietà di linguaggio e rigore terminologico, un argomento scientifico, illustrandone motivazioni e risultati.

Nel corso si utilizzeranno diverse modalità di insegnamento:

1) Lezioni in aula

2) Esercitazioni numeriche in aula

3) Sessioni di analisi dati e di simulazione

Le attività si svolgeranno in lingua inglese.

Corsi introduttivi di Fisica Nucleare

Conoscenze di statistica ed elaborazione dei dati sperimentali

Conoscenze informatiche di base

Conoscenze del framework di analisi ROOT

La frequenza è obbligatoria.

Qualora l'insegnamento venisse impartito in modalità mista o a distanza potranno essere introdotte le necessarie variazioni rispetto a quanto dichiarato in precedenza, al fine di rispettare il programma previsto e riportato nel Syllabus.

I contenuti del Corso sono i seguenti:

Introduction

Energetic regimes for nuclear collisions – Basic phenomenology for heavy ion nuclear collisions – The present status of the experimental facilities in high energy nuclear physics

Reconstruction of collision events

Kinematics of a nuclear collision – The low energy and light particle case – Three-body processes – Multibody collisions – Study of the final state – Kinematical variables in high energy nuclear and particle physics – Rapidity, pseudorapidity, transverse momentum and transverse mass – Transformation of variables – Kinematical acceptance - Reconstruction of decaying particles – Dalitz plots - Invariant mass spectra and identification of decaying particles – Armenteros-Podolanski plot - Background evaluation – Methods and algorithms for background subtraction in high multiplicity events - Event mixing techniques, track rotation, like-sign methods – Event generators for pp and heavy ion collisions – Use of event generators in nuclear physics - Event characterization – Centrality of collision events – Reaction plane and its determination.

High-energy nucleon-nucleon collisions

Basic phenomenology of Nucleon-Nucleon collisions – Particle production – Inclusive experimental distributions – Hard and soft processes – Event generators for nucleon-nucleon collisions – Examples from PYTHIA event generator

Heavy ion collisions from intermediate to relativistic energy

Particle multiplicity – Energy density – Excitation energy – Central and peripheral collisions – Global variables - Event centrality determination – Nuclear matter at high density – Multifragmentation – Inclusive and exclusive experiments – Collective flow – Reaction plane – Subthreshold particle production – Phase transitions at intermediate energy – Particle production from intermediate to relativistic energies – Distributions and relative abundances – Rapidity and transverse momentum distributions – Pion and kaon production – Strangeness production

Ultra-relativistic heavy ion collisions

Nuclear stopping – Energy density – Bjorken estimate – Geometrical description of nuclear collisions – Glauber model – Particle production – Collective effects – Hard probes – Jet quenching – Simulation of high energy nucleus-nucleus collisions – Event generators for heavy ion collisions – Examples from HIJING event generator

Hadronic matter and quark-gluon-plasma

QCD and QGP – The problem of quark deconfinement – Chiral symmetry – Quark matter – Search for experimental evidence of quark matter – Astrophysical aspects – Neutron stars – Strangelets – Connections to cosmic ray physics

Signatures of QGP in heavy ion collisions

Dilepton production – Drell-Yann processes – J/Psi suppression – Strangeness production – Multistrange hyperons – Direct photon emission – Intensity interferometry and space-time size of nuclear sources – Event-by-event physics – Correlations and fluctuations

Recent results from high energy nuclear physics

Review of recent results at RHIC and LHC – Main results and perspectives – The upgrade of the LHC experiments and the future at LHC

Particle detectors in high energy nuclear physics

General properties of particle detectors: operating strategies, signal information, calibration, energy, space and time resolution – Geometrical acceptance – Detector efficiency – Simulation techniques for the evaluation of acceptance and efficiency - Recent developments in gas detectors – Drift chambers – Time Projection Chambers - Multigap resistive plate chambers – Development of silicon detectors – Microstrip detectors – Silicon drift detectors – Hybrid and monolithic pixel detectors – Silicon vertex detectors – Radiation damage in silicon detectors – Cerenkov Ring Detectors – Electromagnetic and hadronic calorimeters – Transition radiation Detectors

Data reconstruction and analysis in high energy nuclear physics

• Invariant mass spectra analysis: Estimation of combinatorial background – Methods and algorithms for background subtraction in high multiplicity events - The event mixing method - The track rotation method – The like sign method - Multiparametric data acquisition and analysis - Trigger design and event selection – Event filtering – Classification of events by centrality – Global variables and centrality evaluation – Determination of reaction plane - Event splitting and evaluation of errors.
• Pattern recognition methods: Hough transform and its application to RICH detectors – Tracking methods – Track recognition and reconstruction – Simple combinatorial methods - Primary and secondary vertex finding – Kalman Filter method – Shower analysis for calorimeters – Shape analysis – Jet reconstruction
• Neural network methods: Artificial neural networks (ANN) – Implementation of ANN by the ROOT package - Applications of ANN to problems in nuclear physics: particle identification, particle tracking, signal reconstruction, forecast methods – Use of neural network algorithms for classification.
• Monte Carlo methods and detector simulation: Basic of Monte Carlo methods – Random numbers and sequences - Monte Carlo methods and application to nuclear physics – Simulation techniques for the evaluation of detector properties - Detector acceptance and efficiency - Simulation of physical processes and detector response – Implementation and use of simulation codes – The GEANT tool – Examples and applications in nuclear physics and related areas

Analysis sessions of experimental data from LHC experiments

Track multiplicity distribution - Inclusive single particle spectra – Transverse momentum and pseudorapidity spectra – Quality of tracks and track selection – Particle identification – Identified particle spectra – V0 selection – Invariant mass analysis – Reconstruction of K0s from pion pairs – Reconstruction of Λ and its antiparticle – Armenteros plot

1) C.Wong, Introduction to Heavy Ion collisions, World Scientific.

2) R.Vogt, Ultrarelativistic heavy ion collisions, Elsevier.

3) G.F.Knoll, Radiation Detection and Measurements, Wiley.

Ulteriori referenze bibliografiche su argomenti specifici saranno forniti durante il Corso.

Presentation of a written Report describing the personal activities of analysis or simulations based on the topics discussed within the Course. Oral discussion of the results and the topics of the Course.

Exams may take place online, depending on circumstances.

The evaluation of the exam will be based on the correctness, completeness, quantitativeness and originality of the analysis carried out, on the understanding of the topics and on the capability to correct communicate the problems and the results.

Production of particles in a nuclear collisions - Evolution of multiplicity with the energetic regime - SIgnatures of Quark Gluon Plasma formation - Connection between high energy nuclear physics and cosmic ray physics - Detectors for high energy nuclear physics - Simulation techniques for particle detectors -