Solving the octant degeneracy with the silver channel

We study the potential of the combination of the golden (νe→νμ) and silver (νe→ντ) channels to solve the octant degeneracy affecting the measurement of θ13 and δ at future neutrino factories. To search for τ leptons produced in ντ charged-current interactions, we consider two different detectors: the Emulsion Cloud Chamber detector (ECC) and the Liquid Argon Time Projection Chamber (LAr TPC). We show that, when using similar detector masses, the upgraded version of the ECC detector (sensitive also to hadronic τ decay modes) and the LAr TPC detector have comparable sensitivities to the octant of θ23, being able to discriminate the two solutions for sin2(2θ13)≳10−3 at 3σ level if θ23=40°. We also show that the same setups are able to see deviation from maximal mixing as small as ∼ (4-6)% (at 3σ) if θ13 is close to its upper bound.