CORDIS - EU research results

Symmetry Investigations in Flavour Theories

Final Report Summary - SIFT (Symmetry Investigations in Flavour Theories)

The SIFT (Symmetry Investigations in Flavour Theories) project concerned itself with Flavour Theories, meaning theories that go beyond the Standard Model of Particle Physics attempting to explain what is designated the Flavour Problem:
- how there are 3 replicas of certain types of fundamental particles
- their properties, such as their masses
For example, the electron has two replicas, the muon and the tau lepton, which are entirely like the electron apart from having larger masses.
In the Standard Model these issues are not addressed and furthermore, these 3 replicas enable a specific phenomenon called CP violation. This is very relevant as CP violation is a necessary ingredient in order for the Universe to have more matter than antimatter (and therefore, ultimately allowing us to exist).

SIFT was divided into 3 main parts:
Advance - to improve the state of the art of Flavour Theories
Phenomenology - to investigate possibilities of testing Flavour Theories through observations
Diversify - to widen the interplay of Flavour Theories with other aspects of physics, in particular cosmology

The research fellow was Dr. Ivo de Medeiros Varzielas.

A lot of progress was achieved in each of SIFT's 3 goals. The more obvious impacts of the project are a total of 18 papers already available to the public, through the following databases:
In addition, one ongoing project is expected to be finished in the near future and result in at least 1 additional paper.

The main results are in aspects related to Higgs physics, CP violation in the presence of family symmetries, rare decays, signatures of models in colliders such as the Large Hadron Collider, and model-building advances (in models with and without grand unification, and with and without supersymmetry). Also explored were connections with Cosmology through leptogenesis and dark matter. These results are fairly technical, disseminated in part through participation in international conferences, and are of main use for other researchers.

The general conclusion is that Flavour Theories continue to be the most promising theories to address the Flavour Problem. A fundamental Flavour Theory remains to be found, but significant theoretical progress was made towards it (if it exists), as well as towards eventually testing it through observations.

The research was disseminated to the scientific community in 14 invited talks (5 in international conferences, 9 in international research centre seminars), plus 3 talks selected for presentation in international conferences.

A major component of the socio-economic impact of the project was through the training of Ph.D. students. During the fellowship Dr. Ivo completed collaborations with a total of 5 Ph.D. students, 4 of which have since been awarded their Ph.Ds.
Dr. Ivo has been specially involved in the training of students supervised in Southampton.

Another significant source of impact of the project was through public engagement. Dr. Ivo was involved in several public engagement activities, most recently by participating in the Science and Technology Facilities Council's (STFC) LHC Roadshow hosted at the Bluedot festival. This activity is worth emphasizing due to the large number of people Dr. Ivo interacted and discussed physics with in the course of the 3 days of the festival. The STFC stats are that the LHC Roadshow at the Bluedot festival was visited by 800 people on Friday, 3000 on Saturday and 1750 on Sunday.