Neutrino Physics

Neutrinos are the second most abundant particle in the universe, with only photons being more common. Yet despite their relative abundance neutrinos are one of the least well measured of all particles. This is because neutrinos are exceptionally weakly interacting, being able to pass through ordinary matter as though it were not there; even when that matter is the size of the Earth! This makes neutrinos hard to detect, and we can not even measure their mass with any kind of certainty and in the Standard Model, neutrinos are assumed to be massless. The abundance of neutrinos in the universe leads to attempts to detect neutrinos that are cosmological in origin (from the sun, supernova, and other origins) and these experiments probe the cosmos in previously unmeasured areas. For example neutrinos from the sun come from the centre of the sun, and so measure what is happening at the centre; light on the other hand comes from the surface of the sun which is only sensitive to what was happening in the centre of the sun one thousand years ago.

The field of neutrino physics has undergone a revolution in the past eight years following the discovery of neutrino oscillations. This is the first significant observation of physics beyond the standard model but it is unknown whether this is a major step or whether it just indicates a small modification to the standard model. Neutrino physics is capable of exploring areas of physics beyond the standard model in the not too distant future. In particular, provided that ϑ₁₃ is not too small, it allows the possibility of determining whether CP violation takes place in the lepton sector.

The IPPP is playing a important role in the decision making mechanisms for future neutrino facilities worldwide. The recent international scoping study for a neutrino factory and super-beam facility to develop the physics case and lay the foundations for a full conceptual-design study of a future facility (ISS) originated in the UK. More recently, Silvia Pascoli has become the deputy coordinator for the Beams for European Neutrino Experiments (BENE) project. In addition a UK-India linkup in all aspects of neutrino physics has been established through the UK-India Education and Research Initiative (UKIERI).