Towards the next generation of neutrino experiments with Liquid Argon detectors.

Neutrinos are particles of the Standard Model that describes all the particles that we know and their interactions. They are neutral, have a very small mass and come in three flavors. Although neutrinos are the most abundant particles in the Universe, they are probably the least understood constituents of matter. One of the reasons why neutrinos remain so poorly understood is the fact that they interact very weakly with matter. Therefore, very large detectors are required to detect and study them.

Seminal discoveries concerning neutrinos have been made in the past; it was discovered that neutrino oscillate between their different flavors, demonstrating that neutrinos have mass. This challenged the Standard Model that predicted that neutrinos were massless. These groundbreaking findings in particle physics made us realize that neutrinos may hold the key to one of the greatest questions of Physics; why is there an imbalance between matter and anti-matter in the Universe? Physicists have tried to answer this question for a long time now, and it seems that the next generation of neutrino experiments may give us a chance at addressing it once more.

There is a new technology currently being developed that is very promising for neutrino detection and for the next generation of neutrino experiments; Liquid Argon (LAr) detectors. These detectors are extremely efficient at detecting neutrinos. A LAr detector, one sixth of the size of a typical neutrino detector of the current generation, can achieve the same result. In addition, these detectors allow clear 3D images of neutrino interactions, hence providing very high rejection capabilities for interactions that are not relevant to the sought signal. It is now thought by many worldwide that LAr detectors represent the future of neutrino experiments.

These new detectors used on a large scale will allow physicists to probe CP violation, phenomenon that may contain the answer to the matter/anti-matter imbalance in the Universe. In addition, a very large LAr detector would offer definitive answers to other great questions of particle physics.

With my unique position and the leading roles I am playing in the LAr detector development, I will drive the involvement and contributions of the UK in this worldwide effort of LAr development. I would continue to contribute significantly to the MicroBooNE experiment, which is currently building a large (170t) LAr detector in the US. This experiment will start acquiring data early in 2014 and will be the only running LAr neutrino experiment in the world. The knowledge we can extract from this experiment, both scientific and technical, is vital to the LAr development program. The access to the MicroBooNE data will provide unique opportunities for UK members to gain essential experience working with LAr detectors.

I also propose to play a leading in the design and construction of the next generation of LAr detectors. The Long-Baseline Neutrino Experiment (LBNE) in the US is planning to build a 10 kiloton LAr detector, about one hundred times bigger than the MicroBooNE detector. The long baseline in this case will be 1300 km, giving the neutrinos the optimal distance for oscillations. I am already heavily involved in this project, and I have significantly contributed to the effort of bringing the project to its current status: design phase.

It is critical that the UK embarks on this worldwide endeavor of LAr development for the future of neutrino physics. This new technology has the power of answering great questions of Science and will impact many different fields of physics, such as astrophysics, cosmology, theoretical and particle physics.