The nuStorm Experiment
Kenneth Long (right) talked about the nuSTORM experiment. One takes neutrinos from stored muons, with as objectives a percent-level cross section measurement, double differential; and a sterile neutrino search beyond what is achievable with the Fermilab SBN. The neutrinos come from 10^18 decays per year in the storage ring, in a range of energy from 3.8 to 5 GeV.
The flux normalization can be pinpointed to less than 1%, and the energy precisely determined. One uses a fast extraction at 100 GeV and a conventional pion production and injection. For the decay ring there are two options, a quadrupole-focusing FODO ring or a fixed-field alternating gradient ring. The latter has a larger acceptance.
The design provides a much larger flux from pions than from muons themselves (see figure, left), and then the positive muons give a democratic share to muon and electron neutrinos.
The measurement of cross sections must be precise if we want to extract CP violation effects from the way neutrinos and antineutrinos interact with matter. This is one of the main motivations of this study.
In conclusion, muon accelerators have the potential to revolutionise neutrino physics, and provide multi-TeV lepton-anti-lepton collisions. nuStorm can deliver neutrino-nucleon scattering measurements with the precision required to serve the long and short baseliner neutrino programmes, and provide a valuable probe for nuclear physics.