The monoenergetic 236 MeV muon neutrino from charged kaon decay-at-rest ($K^+ rightarrow mu^+ u_mu$) can be used to produce a novel set of cross section measurements. Applicable for short- and long-baseline accelerator-based neutrino oscillation exp
eriments, among others, such measurements would provide a standard candle for the energy reconstruction and interaction kinematics relevant for charged current neutrino events near this energy. This neutrino can also be exercised as a unique known-energy, purely weak interacting probe of the nucleus. A number of experiments are set to come online in the next few years that will be able to collect and characterize thousands of these events.
The disappearance of reactor antineutrinos in the Double Chooz experiment is used to investigate the possibility of neutrino-antineutrino oscillations arising due to the breakdown of Lorentz invariance. We find no evidence for this phenomenon and set
the first limits on 15 coefficients describing neutrino-antineutrino mixing within the framework of the Standard-Model Extension.
Monoenergetic muon neutrinos (235.5 MeV) from positive kaon decay-at-rest are considered as a source for an electron neutrino appearance search. In combination with a liquid argon time projection chamber based detector, such a source could provide di
scovery-level sensitivity to the neutrino oscillation parameter space indicative of a sterile neutrino. Current and future intense >3 GeV kinetic energy proton facilities around the world can be employed for this experimental concept.
