by- 21 March 2012
New Physics has in fact shown up recently in the neutrino sector precisely because these neutral particles were discovered to have mass after all, they mix and oscillate. But they do not seem to do so like quarks, what is the mixing pattern and mass hierarchy? Would that lead, like in the quark sector, to CP violation? The measurement of one mixing parameter, Theta13, within 5 years will give some information. One only has a very recent hint (T2K) for a non-zero value for this pivotal angle. Is the neutrino and anti-neutrino exactly the same with all charges equal (Majorana) or are they different? Neutrino-less double beta decay (DBD) is such a discriminant. Answers to such questions are a window on the matter anti-matter asymmetry. Our neutrino task force is involved in both these important aspects: currently OPERA/CNGS (oscillations) and NEMO at LSM (DBD) and later on in the projects LAGUNA-LBNO (oscillations) and superNEMO (DBD), taking part in defining, designing and building a new generation of large detectors. At the moment the absolute values of the neutrino masses are only weighed through data from cosmology. They still need to be measured directly. A discrepancy would hint at interesting issues about the history of the Universe, this would be an interesting cross-border topic for our Labex. Another transversal topic, once the analysis of the neutrino mass pattern has been achieved, is to put it against what one has learned in the quark sector and to study even further the issue of matter anti-matter asymmetry.
Studies of neutrino properties in astrophysical objects and cosmology are deeply connected with new discoveries made using photons as probes, (FERMI and HESS /CTA for gamma rays, the WMAP/PLANCK/LSST for the CMB). This Labex, by attracting world-wide experts will foster and promote a multi-disciplinary approach: it is also crucial to cross-correlate forthcoming detections of high energy neutrino signal (IceCube) with -ray signals to clarify their origin. This is particularly important for objects like Gamma Ray Bursts (GRBs).