Daftar Isi: Muon neutrinos and antineutrinos disappearance analysis from T2K

Daftar Isi:

T2K is an experiment designed to observe neutrino oscillations with a baseline of 295 km across Japan from the J-PARC accelerator complex to the Super-Kamiokande detector. Its main goal is to measure oscillation parameters though $\nu_\mu$ disappearance and $\nu_e$ appearance. Recently, T2K excluded values of $\delta_\text{CP}$ at $3\sigma$ confidence for the first time. I will present two analyses studying for the disappearance of muon neutrinos and antineutrinos, using samples of muon-like events recorded by the T2K experiment. The first analysis uses the conventional PMNS model, to extract the parameters $\theta_{23}$ and $\Delta m^2_{32}$ using two separate parametrization for neutrinos and antineutrinos, testing CPT compatibility and any unconventional matter effect. The second analysis uses a a 'two-flavour' oscillation model allowing $\sin^2\left(\theta_{23}\right)>1$, allowing the oscillation probability to go beyond PMNS and test its consistency.