Recent results from the T2K experiment

Marat Khabibullin,V.E Volkova,Y.V Zhezher,V.A Matveev,D.G Levkov,V.A Rubakov

doi:10.1051/epjconf/201819103001

Abstract

Recent results of the analysis of 2:23×1021 POT data collected by the T2K long-baseline neutrino accelerator experiment are presented in this paper. It is shown that T2K is able to constrain the CP-violating phase δCP in the lepton sector with 2σ significance. Nearest plans for improving the sensitivity to δCP are also given.

Highlights

Neutrinos of three flavours, which take part in the weak interactions, do not have definite masses, their flavour fields can be expressed as linear combinations of neutrino fields with definite masses (ν1; ν2; ν3)
The ID contains ∼11,000 photoelectron multipliers (PMTs) of 50-cm diameter (40% photo-coverage), the OD contains ∼2000 PMTs of 20-cm diameter
Recent results of the analysis of 2.23 × 1021 protons on target (POT) data collected by the T2K experiment are presented in this paper

Summary

Introduction

Neutrinos of three flavours (νe; νμ; ντ), which take part in the weak interactions, do not have definite masses, their flavour fields can be expressed as linear combinations of neutrino fields with definite masses (ν1; ν2; ν3). If neutrinos of a certain flavour are produced at a source (for example at a particle accelerator or nuclear reactor), at some distance from the source one can detect either a deficit of neutrinos of the same flavour (”disappearance”) or an excess of neutrinos of another flavour (”appearance”) This phenomenon (called ”neutrino oscillations”) can be parametrized by three mixing angles, θ12 (historically called as ”solar”), θ23 (”atmospheric”), θ13 (”reactor”), and one CP-violation phase δCP (in the Dirac case). Besides these 4 parameters the oscillation probability depends on neutrino masses (m1, m2, m3), mass ordering (hierarchy), and L/E ratio, where L is the path length of neutrino with energy E. The following sections describe details and recent results of the T2K experiment, which tries to find answers to some of these questions

T2K Experiment

T2K Analysis and Recent Results

T2K Near Future

Findings

Summary