Version 7 (modified by md987, 8 years ago) (diff) 

Electroweak interactions 2011
Lecturers
 JeanMarc Gerard
 Fabio Maltoni
Abstract
This course aims at providing a first introduction to the standard model of electroweak interactions. The prerequisites include Introduction to Particle Physics, Quantum Field Theory I and II, and Relativistic Quantum Mechanics. The course will be divided in two parts, for a total of 22.5 hours (4 ECTS).
Program
I Part : SU(2)_L x U(1)_Y, the gauge boson sector
 Experimental evidence on weak interactions
 Fermi theory of weak interactions : applications and limitations
 Gauge symmetries : Abelian and nonAbelian groups
 SU(2)_L x U(1)_Y : fermion representations and interactions. The problem of gauge boson masses and unitarity violation.
 Spontaneuous symmetery breaking (Goldstone theorem, Abelian Higgs model, Unitarity)
 SU(2)_L x U(1)_Y > U(1)_EM
 Chiral Anomalies
II Part : Flavor dynamics
 Custodial symmetry
 Fermion masses : Yukawa interactions
 Mixing in quark sector : theory and phenomenology
 CP violation
 Mixing in the lepton sector : neutrino mixing, ...
References
 Halzen and Martin
 An introduction to the SM, by Giovanni Ridolfi.
 The Standard Model of Electroweak interactions, by A. Pich.
 Weak Interactions, by Howard Georgi.
Further reading:
 An introduction to quantum field theory, M. Peskin and D. Schroeder [P&S]. Chapters 15, 20, 21.
Original papers:
 S. Weinberg, A Model of Leptons, Phys.Rev.Lett.19:12641266,1967.
Nice suggested readings about the low energy limit of the electroweak theory (Mathieu) :
 L. B. Okun, Leptons and Quarks, pp. 921.
 M. Maggiore, A Modern Introduction to Quantum Field Theory, pp. 195218.
Exercises
I Part
 Fermi effective field theory of weak interactions
 Consider the decay. Calculate the decay rate in the case of a pseudoscalar currentcurrent interaction. Determine the width for the decay of using as an input the experimental width of .
 Consider the . Calculate using the Fierz trick (problem 3.6 of [P&S]) to turn the matrix element squared into a single trace. Consider the decay of a polarized muon. Find the angular distribution of the outcoming electron.
 Calculate the scattering amplitude for .
 EW interactions : SU(2) x U(1)
 Derive the Feynman rules for the self interactions of the W,Z,photons.
 Calculate scattering amplitude and its behaviour at high energy when the gauge symmetry is nonlinearly realized (=massive W,Z but not Higgs).
 Higgs mechanism
 Calculate the scattering in the Abelian Higgs model. Verify that the Goldstone boson contribution is equivalent to the propagation of a massive photon in the internal lines.
 Check that the Higgs contribution in is exactly what is needed to cancel the bad behaviour at high energy.
II Part
 *
Final Projects
 Calculate the total width as a function of the mass, for a SM Higgs [P&S, pag. 775]
 Extend the SM to include a mass for the neutrino's. Consider the two possibilities, Dirac and Majorana. Present and discuss the main differences between the phenomelogy of these two kinds of neutrino's.
 Consider the simple extension of the Higgs sector, where two weak doublets are present. Discuss the various possibilities of giving mass to bosons and fermions, the relation with SUSY, custodial symmetry and the main differences in collider phenomenology.
EW Phenomenology at colliders
Here is a list of exercises that can be "solved" using MadGraph. To do so register at http://madgraph.hep.uiuc.edu and send an email to F.M. to get running access.
 Kinematics at the LHC: single particle quantities.
 DrellYan : Study the rapidity asymmetry at the Tevatron.
 Higgs : Higgs phenomenology at hadron colliders.
 New resonances: Discover new resonances at the LHC.
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Neutral currents in neutrinolepton elastic scattering experiments : additional notes
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