Letter of intent to build an off-axis detector to study nu(mu) ---&amp;gt; nu(e) oscillations with the NuMI neutrino beam

Neutrino mass hierarchy, CP-violation, and octant of θ 23 are the fundamental unknowns in neutrino oscillations. In order to address all these three unknowns, we study the physics reach of a setup, where we replace the antineutrino run of T2HK with antineutrinos from muon decay at rest (µ-DAR). This approach has the advantages of having higher statistics in both neutrino and antineutrino modes, and lower beam-on backgrounds for antineutrino run with reduced systematics. We find that a hybrid setup consisting of T2HK (ν) and µ-DAR (ν) in conjunction with full exposure from T2K and NOνA can resolve the issue of mass hierarchy at greater than 3σ C.L. irrespective of the choices of hierarchy, δ CP , and θ 23 . This hybrid setup can also establish the CP-violation at 5σ C.L. for ∼ 55% choices of δ CP , whereas the same for conventional T2HK (ν +ν) setup along with T2K and NOνA is around 30%. As far as the octant of θ 23 is concerned, this hybrid setup can exclude the wrong octant at 5σ C.L. if θ 23 is at least 3 • away from maximal mixing for any δ CP .

Section: Jhep05(2017)115mentioning

confidence: 99%

A hybrid setup for fundamental unknowns in neutrino oscillations using T2HK (ν) and μ-DAR ν ¯ $$ \left(\overline{\nu}\right) $$

Agarwalla¹,

Ghosh²,

Raut³

2017

“…In this section, we briefly mention the key experimental features of the currently running T2K [52,53] and NOνA [54][55][56][57] experiments that go into carrying out the simulation. The T2K experiment in Japan is collecting the data since 2010.…”

Section: The Off-axis Experiments: T2k and Noνamentioning

confidence: 99%

Discovery potential of T2K and NOvA in the presence of a light sterile neutrino

Agarwalla

Chatterjee

Dasgupta

et al. 2016

Abstract:We study the impact of one light sterile neutrino on the prospective data expected to come from the two presently running long-baseline experiments T2K and NOνA when they will accumulate their full planned exposure. Introducing for the first time, the bi-probability representation in the 4-flavor framework, commonly used in the 3-flavor scenario, we present a detailed discussion of the behavior of the ν µ → ν e andν µ →ν e transition probabilities in the 3+1 scheme. We also perform a detailed sensitivity study of these two experiments (both in the stand-alone and combined modes) to assess their discovery reach in the presence of a light sterile neutrino. For realistic benchmark values of the mass-mixing parameters (as inferred from the existing global short-baseline fits), we find that the performance of both these experiments in claiming the discovery of the CP-violation induced by the standard CP-phase δ 13 ≡ δ, and the neutrino mass hierarchy get substantially deteriorated. The exact loss of sensitivity depends on the value of the unknown CP-phase δ 14 . Finally, we estimate the discovery potential of total CP-violation (i.e., induced simultaneously by the two CP-phases δ 13 and δ 14 ), and the capability of the two experiments of reconstructing the true values of such CP-phases. The typical (1σ level) uncertainties on the reconstructed phases are approximately 40 0 for δ 13 and 50 0 for δ 14 .

“…The NOνA experiment [25][26][27] in the United States is now under construction and will start taking data near the end of this year. The main goal of these experiments is to detect the electron neutrino appearance events in a ν µ beam using the classic off-axis beam technique [50] that delivers a beam with a narrow peak in the energy spectrum.…”

Section: Current Generation: T2k and Noνamentioning

confidence: 99%

“…The combined data from the current ν e appearance experiments, T2K [23,24] and NOνA [25][26][27], can provide a hint at 90% confidence level for neutrino mass ordering [28,29] and at 95% confidence level for octant of θ 23 [30,31]. They can determine these quantities at > 99% C.L.…”

Section: Introductionmentioning

confidence: 99%

Exploring the three flavor effects with future superbeams using liquid argon detectors

Agarwalla

Prakash

Sankar

2014

Recent measurement of a moderately large value of θ 13 signifies an important breakthrough in establishing the standard three flavor oscillation picture of neutrinos. It has provided an opportunity to explore the sub-dominant three flavor effects in present and future long-baseline experiments. In this paper, we perform a comparative study of the physics reach of two future superbeam facilities, LBNE and LBNO in their first phases of run, to resolve the issues of neutrino mass hierarchy, octant of θ 23 , and leptonic CP violation. We also find that the sensitivity of these future facilities can be improved significantly by adding the projected data from T2K and NOνA. Stand-alone LBNO setup with a 10 kt detector has a mass hierarchy discovery reach of more than 7σ, for the lowest allowed value of sin 2 θ 23 (true) = 0.34. This result is valid for any choice of true δ CP and hierarchy. LBNE10, in combination with T2K and NOνA, can achieve 3σ hierarchy discrimination for any choice of δ CP , sin 2 θ 23 , and hierarchy. The same combination can provide a 3σ octant resolution for sin 2 θ 23 (true) ≤ 0.44 or for sin 2 θ 23 (true) ≥ 0.58 for all values of δ CP (true). LBNO can give similar results with 10 kt detector mass. In their first phases, both LBNE10 and LBNO with 20 kt detector can establish leptonic CP violation for around 50% values of true δ CP at 2σ confidence level. In case of LBNE10, CP coverage at 3σ can be enhanced from 3% to 43% by combining T2K and NOνA data, assuming sin 2 θ 23 (true) = 0.5. For LBNO setup, CP violation discovery at 3σ is possible for 46% values of true δ CP if we add the data from T2K and NOνA.