Potential of optimized NOvA for large theta(13) & combined performance with a LArTPC & T2K

TL;DR

This study evaluates how optimized NOvA, combined with T2K and a liquid argon detector, enhances sensitivity to neutrino mass hierarchy and CP violation, especially for large theta(13).

Contribution

It demonstrates the improved potential of combined experimental data, including a new liquid argon detector, for neutrino hierarchy and CP violation discovery.

Findings

20% increased sensitivity for favorable deltacp values.

More than doubling of deltacp range for CP violation discovery with T2K addition.

Near 2 sigma hierarchy hint with combined data from all detectors.

Abstract

NOvA experiment has reoptimized its event selection criteria in light of the recently measured moderately large value of theta(13). We study the improvement in the sensitivity to the neutrino mass hierarchy and to leptonic CP violation due to these new features. For favourable values of deltacp, NOvA sensitivity to mass hierarchy and leptonic CP violation is increased by 20%. Addition of 5 years of neutrino data from T2K to NOvA more than doubles the range of deltacp for which the leptonic CP violation can be discovered, compared to stand alone NOvA. But for unfavourable values of deltacp, the combination of NOvA and T2K are not enough to provide even a 90% C.L. hint of hierarchy discovery. Therefore, we further explore the improvement in the hierarchy and CP violation sensitivities due to the addition of a 10 kt liquid argon detector placed close to NOvA site. The capabilities of such a detector are equivalent to those of NOvA in all respects. We find that combined data from 10 kt liquid argon detector (3 years of nu + 3 years of nubar run), NOvA (6 years of nu + 6 years of nubar run) and T2K (5 years of nu run) can give a close to 2 sigma hint of hierarchy discovery for all values of deltacp. With this combined data, we can achieve CP violation discovery at 95% C.L. for roughly 60% values of deltacp.