Technical design aspects of Feasibility Study-II

Abstract

Feasibility Study-II examined a high-performance Neutrino Factory providing 1 × 10 20 neutrinos per year aimed at a long-baseline detector. The Study was sponsored jointly by BNL and the Neutrino Factory and Muon Collider Collaboration (MC) and is based on a 1 MW proton driver operating at 24 GeV, i.e., an upgraded version of the AGS accelerator. Compared with the earlier FNAL-sponsored study (Feasibility Study-I), there is a sixfold improvement in performance. Here we describe details of the implementation of Study-II concepts and discuss their efficacy. Alternative approaches that will be pursued in follow-on R&D activities are also described briefly.

Physics at a future Neutrino Factory and super-beam facility

“…Studies [30][31][32][33][34][35] so far have shown that the Neutrino Factory gives the best performance over virtually all of the parameter space; its time scale and cost remain, however, important question marks. Super-beams have many components in common with the Neutrino Factory.…”

“…This detector is assumed to have an appearance ν µ threshold rising linearly from 0 at 4 GeV to its final value at 20 GeV. Systematic uncertainties of 2.5% on the signal and 20% on the background 35 . For more details see [217,349].…”

“…Of the beta-beam set-up only the optimised, γ = 350 option with the relatively long baseline of 730 km is competitive with the WBB, having a comparable sensitivity limit. The Neutrino 35 The fact that the number of background events is small means that the large systematic uncertainty on the background-event rate has almost no impact on the performance Figure 103: The discovery reach of the various proposed facilities in sin 2 2θ13. In the area to the right of the bands, sin 2 2θ13 = 0 can be excluded at the 3σ confidence level.…”

The discovery channel at the Neutrino Factory: νμ→ ντpointing to sterile neutrinos

“…The muon decays µ + → e + ν eνµ and µ − → e −ν e ν µ provide a very well known two-flavor neutrino flux [91] with energies in the range E ν ∈ [0, E µ ]. Neutrino Factory designs have been proposed in Europe [92,93], the US [94][95][96][97], and Japan [98]. The dedicated International Scoping Study for a future Neutrino Factory and Super-Beam facility [43] showed that, provided sufficient resources, an accelerator complex capable of providing about 10 21 muon decays of a given polarity per year can be built.…”