The process of the muon neutrino or muon antineutrino beam production consists of the following steps:[1][2] It is usually intended to have a pure beam, containing only one type of neutrino: either νμ or νμ .
A method that allows to further narrow the energy distribution of the produced neutrinos is the usage of the so-called off-axis beam.
However, the farther from the axis (centre) of the beam, the smaller is the number of neutrinos, but also the distribution of energy changes.
This idea, which dates back to the 1960s,[8] has been developed in the framework of the tagged neutrino beam concept but it has not been demonstrated, yet.
[9] Below is the list of muon (anti)neutrino beams used in past or current physics experiments: