First Antineutrino Oscillation Results from T2K

Abstract

As limits improve on the neutrino mixing angles and mass-squared differences, the focus of T2K has shifted towards studying antineutrino oscillation. This will give an insight into CP violation (if P($\barν_μ \rightarrow \barν_{e}) \neq \mbox{P}(ν_μ \rightarrow ν_e)$) and CPT violation (if P($\barν_μ \rightarrow \barν_μ) \neq \mbox{P}(ν_μ \rightarrow ν_μ)$) in the lepton sector. This poster summarises the most recent T2K antineutrino oscillation results, from data collected using a ${\bar{\nu }}_{\mu }$-enhanced neutrino beam corresponding to $4.01\times 10^{20}$ protons on target (roughly $1/3$ of the total protons on target collected by T2K). We present world-leading measurements of $\Delta {\bar{m}}_{32}^2$ and ${\sin }^2{\bar{\theta }}_{23}$ and the first analysis of ${\bar{\nu }}_e$ appearance from T2K. Both results use a Bayesian oscillation analysis based on a Markov Chain Monte Carlo method in which data from the near detector and far detector are fit simultaneously.

Poster presented at NuPhys2015 (London, 16-18 December 2015). 4 pages, LaTeX, 4 png figures