The ‘flavours’ of the particles of the Universe
In the 1970s, the Standard Model was developed to explain the nature of the world around us. Accordingly, the Universe consists of 12 fundamental matter particles (six quarks and six leptons, the best-known of which is the electron) and four force-carrying particles that act on them. Physicists have assigned ‘flavours’ to distinguish among the different types of quarks and leptons. While many predictions of the Standard Model and all 12 matter particles have now been observed experimentally, there are a couple of problems recognised by the scientific community as a whole. Looking beyond the Standard Model, one question that remains open is the nature of the symmetry between matter and antimatter. According to the Model, for every type of matter particle there is a corresponding antimatter particle of equal mass and opposite charge (e.g. a positive proton and a negative anti-proton). However, antimatter particles are rarely observed. In addition, scientists are still trying to understand the nature of the ‘dark matter’ (DM) that makes up 70 % of the mass of the Universe, producing visible gravitational effects. European researchers set out to address these fundamental open questions of particle physics with funding for ‘The physics of flavor in visible and dark sectors’ (Flavidas) project. The first area of research concerned the implications of flavour symmetries. Scientists explained a reported deviation from the Standard Model using the so-called Minimal Flavour Violation hypothesis explaining how and when matter particles change flavour. The published results provided a good fit to all measures allowing for robust interpretations. The second area of research focused on an effective integration of experimental and theoretical work regarding detection of DM. The Flavidas team investigated DM signals and successfully developed a description of direct DM searches and their relevance to ‘signatures’ of DM (parameters for detection unique to DM). Overall, Flavidas researchers investigated two of the most important open questions in high energy particle physics leading to important theoretical descriptions and publications. Acquired knowledge should advance understanding of gravity and DM and facilitate appropriate development of future experimental work.