Getting the best out of T2K and NOvA

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 .

“…assuming θ 23 to be maximal [22][23][24][25][26][27][28][29]. Under the same conditions, these experiments can reject the wrong hierarchy at ∼ 3.4σ confidence level.…”

Section: Jhep05(2017)115mentioning

confidence: 78%

“…Therefore, one does not expect this degeneracy to be lifted by the addition of antineutrino data [23,24]. Similarly, the probability for NH and LO and can be matched by IH and HO, leading to a degeneracy in the octant measurement.…”

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

“…For LBNE10, a 5σ discovery of hierarchy is possible for only ∼ 50% of the δ CP (true), irrespective of these four true θ 23 -hierarchy combinations. For the unfavorable hierarchy-δ CP combinations [71], i.e. NH with δ CP in the upper half plane or IH with δ CP in the lower half plane, the performance of LBNE10 suffers.…”

Section: Discovery Reach For Neutrino Mass Hierarchymentioning

confidence: 99%

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

Agarwalla

Prakash

Sankar

2014

Self Cite

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.

“…The first could be achieved with a medium baseline reactor experiment [8][9][10][11][12][13][14][15][16][17][18][19][20][21] and long baseline accelerator experiments [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]44] could measure all three of them. Atmospheric neutrino experiments could offer alternative ways to accomplish the same.…”

Section: Introductionmentioning

confidence: 99%

A novel approach to study atmospheric neutrino oscillation

Hagiwara

Rott

2014

We develop a general theoretical framework to analytically disentangle the contributions of the neutrino mass hierarchy, the atmospheric mixing angle, and the CP phase, in neutrino oscillations. To illustrate the usefulness of this framework, especially that it can serve as a complementary tool to neutrino oscillogram in the study of atmospheric neutrino oscillations, we take PINGU as an example and compute muon-and electron-like event rates with event cuts on neutrino energy and zenith angle. Under the assumption of exact measurement of neutrino momentum with a perfect e-µ identification and no background, we find that the PINGU experiment has the potential of resolving the neutrino mass hierarchy and the octant degeneracies within 1-year run, while the measurement of the CP phase is significantly more challenging. Our observation merits a serious study of the detector capability of estimating the neutrino momentum for both muon-and electron-like events.