Observation of ν_μ→ν_e Oscillation in the T2K Experiment

Combiningthe T2K νμ→νe oscillation measurement with the latest findings on oscillationparameters including the world average value of θ13 from reactor experiments,the constraint on the value of δCP at the 90% confidence level is obtained.

---

In this thesis the
author contributes to the analysis of neutrino beam data collected between 2010
and 2013 to identify νμ→νe  events at the Super-Kamiokande detector. In particular,
the author improves the pion–nucleus interaction uncertainty, which is one of
the dominant systematic error sources inT2K neutrino oscillation measurement.
In the thesis, the measurement of νμ→νe  oscillation in the T2K (Tokai to
Kamioka) experiment is presented and a new constraint on δCP is obtained. This
measurement and the analysis establish, at greater than 5σ significance, the
observation of νμ→νe  oscillation for the first time in the world. Combining
the T2K νμ→νe  oscillation measurement with the latest findings on oscillation
parameters including the world average value of θ13 from reactor experiments,
the constraint on the value of δCP at the 90% confidence level is obtained.
This constraint on δCP is an important step towards the discovery of CP
violation in the lepton sector.