Neutrinos

T2K scientific results in 2017

T2K acquired more data in 2017 in neutrino and antineutrino modes. T2K has accumulated $1.65×10^21$ protons on target, comprising approximately 20% of the total requested exposure during the first phase. The data taken has been shared between neutrino (57.14%) and antineutrino modes (42.86%). The preliminary results in 2017 constrain the $δ_{CP}$ phase to negative values with more than 95% The collaboration also published the current world best constrain on $θ_{23}$ see Figure 4. These results are consequence of the increased statistics but also on the improvement of systematic errors and the inclusion of new neutrino interaction samples in the analysis.

IFAE Contribution to T2K

IFAE continued with its contribution to reduce the systematic errors associated to the neutrino cross-sections. IFAE group adapted the neutrino cross-section model based on Local Fermi Gas into the official T2K Monte Carlo generator NEUT. IFAE also improved the data analysis by enlarging the near detector angular acceptance and setting the bases of a new generation of analysis based on 4π acceptance. The first results obtained by the IFAE group, see Figure 5, have been approved for publication.