78958 - CROMODINAMICA QUANTISTICA

Conoscenze e abilità da conseguire

Al termine del corso lo studente possiede la conoscenza degli aspetti fondamentali delle interazioni forti, della loro fenomenologia e della teoria che le descrive, la cromodinamica quantistica (QCD). In particolare è capace, partendo dalla Lagrangiana di QCD, di definire osservabili di rilevanza sperimentale e di determinarli tramite calcoli perturbativi. Il corso comprende una serie di applicazioni rilevanti per la fisica ai colliders ad alta energia, inclusa la simulazione di eventi via metodi Monte Carlo.

Contenuti

1. Strong interactions at low energy: perturbative vs non-perturbative approaches, chiral symmetry, effective lagrangian approach, the quark model and hadrons.

2. From abelian to non-abelian gauge theories: QCD lagrangian, Feynman rules, ghosts, colour algebra, large-Nc limit, amplitude techniques.

3. UV properties of QCD: Renormalisation, beta function and the running coupling constant, asymptotic freedom, renormalisation group.

4. e+e- annihilation to hadrons: inclusive total cross section at LO and NLO; infrared-collinear safety, event shape variables, jet definitions and cross sections; exclusive predictions, resummation, parton showers, hadronisation.

5. Deep inelastic scattering: the parton model, structure functions, parton density functions, QCD picture at NLO, collinear factorisation, splitting functions, scaling violations, DGLAP evolution, parton showers in the initial state.

6. QCD phenomenology at hadron colliders: Drell-Yan, jet, top-quark pair, and Higgs boson production.

Testi/Bibliografia

Books:

• F. Halzen and A.D. Martin, Quarks and Leptons (Wiley, 1984)

• M. E. Peskin and D. V. Schroeder, An Introduction to Quantum Field Theory, (Addison Wesley, 1995)

• Chris Quigg, Gauge Theories of the Strong, Weak and Electromagnetic Interactions (Princeton University Press, 2nd edition 2013)

• R. K. Ellis, W. J. Stirling & B. R. Webber, QCD and Collider Physics, (Cambridge, 1996)

• J. M. Campbell, J. W. Huston and F. Krauss, The black book of Quantum Chromodynamics: A Primer for LHC Era, (Oxford Press, 2017)

Lecture notes on QCD:

• Paolo Nason : Introduction to QCD [1998]
• Michelangelo Mangano : Introduction to QCD [1999]
• Gavin Salam : Elements of QCD for hadron colliders [2011]
• Peter Skands : Introduction to QCD [2012]
• Fabio Maltoni : Basics of QCD for the LHC : pp->H+X as a case study [2014]

Metodi didattici

Blackboard lectures. Slides might be used to present auxiliary material. 

Modalità di verifica e valutazione dell'apprendimento

Exercise from the log book, presentation of the final project (to be chosen by the student among a list that will be published at the end of the course) and interview.

Orario di ricevimento

Consulta il sito web di Fabio Maltoni