A high-resolution version for printing - CP3-Origins

CP violation is also relevant for cosmology: it is one of the three conditions of Sakharov necessary
for a dynamical explanation of the observed baryon asymmetry of the universe (together
with baryon number violation and deviation from thermal equilibrium). The amount of CP violation
provided by the SM is, however, too tiny to explain the baryon asymmetry observed in
the universe: there must be at least one additional source of CP violation beyond the SM, yet to
be discovered by laboratory experiments.
CP violating phenomena beyond the SM that could be detected by ongoing and planned laboratory
experiments include: deviations from the SM description of the quark mixings, to be
probed mainly by the LHCb experiment at CERN; neutrino oscillations, because future long
baseline experiments could detect the CP violating PMNS-phase; fermion Electric Dipole Moments.
The origin of CP violation is poorly understood and is intimately linked to various open problems
in particle physics: the violation of flavour, the number of fermion generations, the nature
of the Higgs field and its role in the spontaneous breaking of the electroweak symmetry. In general,
theories beyond the SM possess many sources of CP violation. This is for instance the case
in supersymmetric models.
We plan to:
• Study and characterise new sources of CP violation associated to: observable deviations from
the CKM-description of the quark mixings; non-unitary neutrino oscillations; observable fermion
EDMs.
• From the model building point of view, we plan to analyse in particular: models with TeVscale
neutrinos, like the one we have put forward (See the Natural Fourth Family subsection),
which can be probed at LHC; models with minimal flavour violation and/or models with
flavour symmetries.
• Explore mechanisms to solve the CP and flavour problems of low-energy theories beyond the
SM. In this respect we will consider various frameworks beyond the SM: extended Higgs sectors
or alternative electroweak symmetry breaking models, grand unification, supersymmetry,
extra-dimensions, etc.
• Investigate mechanisms for the generation of the baryon asymmetry of the universe, and to
consider related astroparticle issues. For instance, we plan to explore the leptogenesis scenario.
These investigations will involve many cosmological aspects which we will address: phase transitions,
inflation, dark matter, dark energy, etc.
CP³-Black book 15