Latest results from T2K

TL;DR

T2K's recent neutrino data collection and analysis enhancements have significantly increased sensitivity to CP violation, leading to the first exclusion of CP-conserving values of _{CP} at 2 confidence level.

Contribution

The paper reports new results from T2K with doubled data and improved analysis methods, providing unprecedented sensitivity to CP violation in neutrino oscillations.

Findings

CP-conserving _{CP} values are excluded at 2 C.L.

Enhanced data collection and analysis improved sensitivity to CP violation.

First time _{CP} values are statistically disfavored as CP-conserving.

Abstract

Thank to the stable operation at intense beam power, T2K data with neutrino-mode operation almost doubled in one year. A number of critical improvements to the oscillation analysis have been introduced and resulted in an unprecedented level of sensitivity in searching for CP violation in the neutrino sector. T2K firstly reports that the CP-conserving values of parameter $\delta_{CP}$ in the PMNS mixing matrix fall out of its 2$\sigma$ C.L. measured range.