Speaker
Description
T2K (Tokai to Kamioka) is a long-baseline neutrino oscillation experiment situated in Japan with a baseline of 295 km and a neutrino beam of energy peaked at 600 MeV. The experiment can record data using either a mainly neutrino or mainly anti-neutrino beam, allowing to study the difference between the oscillations of neutrinos and anti-neutrinos. In T2K, one powerful method to test the 3-flavour neutrino oscillation framework (known as PMNS formalism) is to compare the disappearance of muon neutrinos and anti-neutrinos. In order to test the compatibility, we measure the oscillation parameters describing their disappearance ($\theta_{23}$, $\Delta m^{2}_{32}$) while allowing them to vary separately for neutrinos and antineutrinos. The compatibility with the PMNS framework is tested by comparing the fitted parameter values between the neutrinos and antineutrinos. For this study, we use the T2K run 1-10 data, corresponding to an exposure of 1.9664$\times 10^{21}$ POT in neutrino mode and 1.6345$\times 10^{21}$ POT in anti-neutrino mode.
We use the selected one ring muon candidate events in both neutrino and anti-neutrino mode to perform the joint fit which constrains the wrong-sign background. The best-fit values for $\Delta m^{2}$ ($\Delta \bar m^{2}$) are 2.48$\times 10^{-3} eV^{2}$ (2.53$\times 10^{-3} eV^{2}$), and for sin$^{2}\theta_{23}$ are 0.468 (0.449). The analysis results are in agreement with the PMNS formalism.
| Are you are a member of the APS Division of Particles and Fields? | Yes |
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