Determination of the θ 23 octant in LBNO

According to the recent results of the neutrino oscillation experiment MINOS, the neutrino mixing angle 23 may not be maximal (45 ). Two nearly degenerate solutions are possible, one in the lower octant (LO) where 23 45 . Long baseline experiments measuring the ! e are capable of resolving this degeneracy. In this work we study the potential of the planned European LBNO experiment to distinguish between the LO and HO solutions.