The Need for an Early Anti-neutrino Run of NOvA
NOvA, with equal three year neutrino and anti-neutrino runs, can determine the mass hierarchy for only favorable half-plane of \delta_CP , due to hierarchy-\delta_CP degeneracy. In this talk, I consider the residual degeneracies in the first three years of neutrino data of NOvA. Such data is still affected by the sin2^2\theta_13-hierarchy degeneracy if the error in sin2^2\theta_13 is the present 10%, but becomes independent of it, if the error is reduced to 5%.
It is strongly influenced by octant-hierarchy degeneracy and has no hierarchy determination capability if one of the combinations, lower octant-normal hierarchy (LO- NH) or higher octant-inverted hierarchy (HO-IH), is true. However, equal neutrino and anti-neutrino runs are free of these degeneracies. If NOvA were to have equal 1.5 years of neutrino and anti-neutrino runs, then it will have reasonable hierarchy determination capability for all combinations of octant and hierarchy.