Bridging grant for T2K Project

T2K实验使用了日本东海的日本质子加速器研究综合体(J-PARC)生产的高强度Muon-中微子束。光束偏离轴线2.5度指向50千吨重的水切伦科夫探测器Super-Kamiokande(SK)，该探测器位于295公里外的神冈煤矿。通过使用离轴光束，Muon-中微子的能谱较窄，并且集中在SK处Muon-中微子消失的最大概率附近。Muon-中微子束也是由距离中微子束产生目标280米(ND280)的近探测器测量的。NEAR探测器提供Muon-中微子速率的整体归一化，并测量振荡前中微子的能谱。ND280探测器复合体的一部分是一套三个大体积时间投影室(TPC)，它们提供出色的带电粒子跟踪，并利用其动量和De/DX测量进行粒子识别。

The T2K experiment uses a high intensity muon-neutrino beam produced at the Japan Proton Accelerator Research Complex (J-PARC) in Tokai, Japan. The beam is directed 2.5 degrees off-axis to the 50 kTon water Cerenkov detector, Super-Kamiokande (SK), which sits 295 km away in the Kamioka mine. By using an off-axis beam the energy spectrum of the muon-neutrinos is narrower, and concentrated around the maximum probability for muon-neutrino disappearance at SK. The muon-neutrino beam is also measured by a near detector at 280 m (ND280) from the neutrino beam production target. The near detector provides the overall normalisation for the muon-neutrino rate, and measures the energy spectrum of the neutrinos before oscillation. Part of the ND280 detector complex is a set of three large volume Time Projection Chambers (TPCs) which provide excellent charged particle tracking, and particle identification using its momentum and dE/dx measurements.