The T2K Experiment

Indication of Electron Neutrino Appearance from an Accelerator-produced Off-axis Muon Neutrino Beam

July 21, 2011

The T2K experiment observes indications of ν_μ → ν_e appearance in data accumulated with 1.43×10²⁰ protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with Δm²₂₃ = 2.4×10^-3 eV², sin²(2θ₂₃) = 1 and sin²(2θ₁₃) = 0, the expected number of such events is 1.5±0.3(syst.).

arXiv preprint: https://arxiv.org/abs/1106.2822
Reference: Phys. Rev. Lett. 107, 041801 (2011)
DOI: https://doi.org/10.1103/PhysRevLett.107.041801

Design and performance of the muon monitor for the T2K neutrino oscillation experiment

July 21, 2011

This article describes the design and performance of the muon monitor for the T2K (Tokaito-Kamioka) long baseline neutrino oscillation experiment. The muon monitor consists of two types of detector arrays: ionization chambers and silicon PIN photodiodes. It measures the intensity and profile of muons produced, along with neutrinos, in the decay of pions. The measurement is sensitive to the intensity and direction of the neutrino beam.

arXiv preprint: https://arxiv.org/abs/1008.4077
Reference: Nucl. Instrum. Meth. A 624, 591 (2010)
DOI: https://doi.org/10.1016/j.nima.2010.09.074

Time projection chambers for the T2K near detectors

July 21, 2011

A key element of the near detectors is the ND280 tracker, consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking.

This paper describes the design and construction of the TPCs, the micromegas modules, the readout electronics, the gas handling system, and shows the performance of the TPCs as deduced from measurements with particle beams, cosmic rays, and calibration system.

arXiv preprint: https://arxiv.org/abs/1012.0865
Reference: Nucl. Instrum. Meth. A 637, 25 (2011)
DOI: https://doi.org/10.1016/j.nima.2011.02.036