LAGUNA and LAGUNA–LBNO: Future megaton neutrino detectors in Europe

Abstract

The FP7 Design Studies LAGUNA (Large Apparatus studying Grand Unification and Neutrino Astrophysics) and LAGUNA–LBNO (Large Apparatus studying Grand Unification and Neutrino Astrophysics and Long Baseline Neutrino Oscillations) are studying Pan-European research infrastructures in deep underground cavities able to host a very large multipurpose next-generation neutrino observatory. These future megaton scale detectors are dedicated to nucleon decay, neutrinos from supernovæ, solar and atmospheric neutrinos, as well as neutrinos from a future Super-Beam or $\mathrm{\beta }\mathrm{-}\mathrm{Beam}$ to measure the mixing angle ${\theta }_{13}$, the CP violating phase $\delta$ and the mass hierarchy.

Introduction

Neutrinos are messengers from astrophysical objects as well as from the early universe and can give us information on processes, which cannot be studied otherwise. Underground experiments, like SuperKamiokande (SK) [1], have made important discoveries. Next-generation very large volume underground experiments will answer fundamental questions on particle and astroparticle physics. They will search for a possible finite proton lifetime with a sensitivity one order of magnitude better than the current limit. With a neutrino beam they will measure with unprecedented sensitivity the last unknown mixing angle (${\theta }_{13}$) of neutrinos and unveil through neutrino oscillations the existence of CP violation in the leptonic sector, which in turn could provide an explanation of the matter–antimatter asymmetry in the Universe. Moreover they will study astrophysical objects, in particular the Sun and Supernovæ [2]. The construction of a large scale detector devoted to particle and astroparticle physics in Europe is one of the priorities of the ASPERA¹ roadmap (2008).