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PROPOSITION DE STAGE 2012
Master 2 (stage de pré-thèse)
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STAGE DE THESE
Groupe du laboratoire : Théorie
Responsable du stage : Emi KOU
Adresse et lieu du stage : LAL – Bât 208
 : 01 64 46 85 99
e-mail : kou @ lal.in2p3.fr
Titre du stage : Phenomenology of flavour physics to search for signals beyond SM
Précisions sur le sujet proposé :
The current target of particle physics is a discovery of a signal beyond the Standard
Model (SM). Various models beyond SM have been proposed based on strong theoretical
motivations. Having the Large Hadron Collider (CERN/Geneva) providing vast number
of experimental results, it is now that some of those new theoretical ideas are to be
confronted to the experimental data. In this thesis, we will attempt to provide theoretical
interpretations of the newly obtained experimental data.
Searches for new particles from physics beyond SM must be performed from two
directions, i) investigation of a direct production of the new particles at the high energy
experiments and ii) an indirect search investigating the quantum loop effects. The main
focus of this thesis follows the ii) type of search, namely using flavour physics.
Various experiments have been carried out and further ambitious programs have been
proposed in flavour physics. In particular, for B physics, the LHCb experiment is
currently revealing very interesting results while ambitious experimental proposals have
been made, the super B factories, which target 50-100 times higher luminosity than the
current machines.
Flavour physics played an important role in the establishment of SM. A remarkable
property of SM is that it can incorporate the suppression of the flavour changing neutral
current (FCNC) through the Glashow-Iliopoulos-Maiani (GIM) mechanism as well as the
simple explanation of the observed CP violation through Kobayashi-Maskawa
mechanism. On the other hand, in many of the models beyond SM, these are not obvious
and as a result, unexpectedly large FCNC or CP violating phenomena could easily occur.
Confronting new physics models such as 4th generation extension, Supersymmetric
extension, extra-dimension extension of SM to the latest experimental data on flavour
physics is the subject of this thesis.
Précisions sur le stage :
The new physics signals in B meson experiments, a tiny deviations from SM
prediction in the FCNC branching ratios or CP violating observables, tend to be actually
veiled by the clouds of the strong interaction which hides the desired short distance
interaction involving the new particles. This is the biggest challenge in this field but one
which can be adequately tackled by using various techniques of quantum
chromodynamics (QCD). The student will learn throughout this thesis the fundamentals
of QCD as well as some computational techniques needed for flavour physics. During the
stage, we will give the necessary guidances for the thesis.