Abstract

One of the most fundamental mysteries about our universe is the question where all the matter came from. If matter and anti-matter behaved in the same way, they should have been created in equal amounts during the big bang and subsequently annihilated, leaving nothing but a sea of photons. The Tokai To Kamioka (T2K) experiment in Japan uses neutrino and anti-neutrino beams to investigate the possible difference between matter and anti-matter. As the first experiment ever, it was able to exclude large parts of the parameter space at the 3-sigma confidence level. The result suggests that the matter-antimatter asymmetry is (close to) as large as it can be in the leptonic sector. This provides an important input to the study of processes of leptogenesis, i.e the creation of a matter excess via asymmetries in the leptonic sector. In this talk I will present a brief introduction to the T2K experiment and present these newest results.