Changes between Initial Version and Version 1 of ElectroWeak


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Timestamp:
10/26/11 17:42:42 (9 years ago)
Author:
omatt
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  • ElectroWeak

    v1 v1  
     1= Electroweak interactions 2011 =
     2
     3== Lecturers ==
     4
     5   * Jean-Marc Gerard
     6   * Fabio Maltoni
     7
     8== Abstract ==
     9
     10This 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).
     11
     12== Program ==
     13
     14I Part : SU(2)_L x U(1)_Y, the gauge boson sector
     15
     16   * Experimental evidence on weak interactions
     17   * Fermi theory of weak interactions : applications and limitations
     18   * Gauge symmetries : Abelian and non-Abelian groups
     19   * SU(2)_L x U(1)_Y : fermion representations and interactions. The problem of gauge boson masses and unitarity violation.
     20   * Spontaneuous symmetery breaking (Goldstone theorem, Abelian Higgs model, Unitarity)
     21   * SU(2)_L x U(1)_Y -> U(1)_EM
     22   * Chiral Anomalies
     23
     24II Part : Flavor dynamics
     25
     26   * Custodial symmetry
     27   * Fermion masses : Yukawa interactions
     28   * Mixing in quark sector : theory and phenomenology
     29   * CP violation
     30   * Mixing in the lepton sector : neutrino mixing, ...
     31
     32== References ==
     33
     34   * Halzen and Martin
     35   * [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/EWUCL/smcom.pdf An introduction to the SM], by Giovanni Ridolfi.
     36   * [http://arxiv.org/abs/0705.4264 The Standard Model of Electroweak interactions], by A. Pich.
     37   * [http://www.people.fas.harvard.edu/~hgeorgi/weak.pdf][Weak Interactions], by Howard Georgi.
     38
     39Further reading:
     40
     41   * An introduction to quantum field theory, M. Peskin and D. Schroeder [P&S]. Chapters 15, 20, 21.
     42
     43Original papers:
     44
     45   * S. Weinberg, A Model of Leptons, Phys.Rev.Lett.19:1264-1266,1967.
     46   *
     47
     48Nice suggested readings about the low energy limit of the electroweak theory (Mathieu) :
     49
     50   * L. B. Okun, Leptons and Quarks, pp. 9-21.
     51   * M. Maggiore, A Modern Introduction to Quantum Field Theory, pp. 195-218.
     52
     53== Exercises ==
     54
     55I Part
     56
     57   * Fermi effective field theory of weak interactions
     58      1 Consider the %$ \pi \to \ell \nu_\ell $% decay. Calculate the decay rate in the case of a pseudoscalar current-current interaction. Determine the width for the decay of %$\tau \to \pi \nu_\tau $% using as an input the experimental width of %$\pi \to \ell \nu_\ell $%.
     59      1 Consider the %$\mu^- \to e^- {\bar \nu_{e}} \nu_\mu$%. Calculate %$|M|^2$% using the Fierz trick (problem 3.6 of [P&S]) to turn the matrix element squared into a single trace. Consider the decay of a polarized muon. Find the angular distribution of the outcoming electron.
     60      1 Calculate the scattering amplitude for %$e^- + \nu_\mu \to \mu^- + \nu_e$%.
     61
     62   * EW interactions : SU(2) x U(1)
     63      1 Derive the Feynman rules for the self interactions of the W,Z,photons.
     64      1 Calculate %$W^+ W^- \to W^+ W^-$% scattering amplitude and its behaviour at high energy when the gauge symmetry is non-linearly realized (=massive W,Z but not Higgs).
     65
     66   * Higgs mechanism
     67      1 Calculate the scattering %$H \gamma \to H \gamma$% in the Abelian Higgs model. Verify that the Goldstone boson contribution is equivalent to the propagation of a massive photon in the internal lines.
     68      1 Check that the Higgs contribution in %$W^+ W^- \to W^+ W^-$% is exactly what is needed to cancel the bad behaviour at high energy.
     69
     70II Part
     71
     72* *
     73
     74== Final Projects ==
     75
     76   * Calculate the total width as a function of the mass, for a SM Higgs [P&S, pag. 775]
     77   * 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.
     78   * 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.
     79
     80== EW Phenomenology at colliders ==
     81
     82Here is a list of exercises that can be "solved" using Software.MadGraph. To do so register at http://madgraph.hep.uiuc.edu and send an e-mail to F.M. to get running access.
     83
     84   * [http://cp3wks05.fynu.ucl.ac.be/twiki/bin/view/Physics/SimpleKinematics Kinematics at the LHC]: single particle quantities.
     85   * [http://cp3wks05.fynu.ucl.ac.be/twiki/bin/view/Physics/WAsymm Drell-Yan] : Study the rapidity asymmetry at the Tevatron.
     86   * [http://cp3wks05.fynu.ucl.ac.be/twiki/bin/view/Physics/HiggsPheno Higgs] : Higgs phenomenology at hadron colliders.
     87   * [[http://cp3wks05.fynu.ucl.ac.be/twiki/bin/view/Physics/X New resonances]: Discover new resonances at the LHC.