There is accumulating evidence for a difference between neutrino and
antineutrino oscillations at the ∼1 eV2 scale. The MiniBooNE
experiment observes an unexplained excess of electron-like events at low
energies in neutrino mode, which may be due, for example, to either a neutral
current radiative interaction, sterile neutrino decay, or to neutrino
oscillations involving sterile neutrinos and which may be related to the LSND
signal. No excess of electron-like events (−0.5±7.8±8.7), however, is
observed so far at low energies in antineutrino mode. Furthermore, global 3+1
and 3+2 sterile neutrino fits to the world neutrino and antineutrino data
suggest a difference between neutrinos and antineutrinos with significant
(sin22θμμ∼35) νˉμ disappearance. In order to
test whether the low-energy excess is due to neutrino oscillations and whether
there is a difference between νμ and νˉμ disappearance, we
propose building a second MiniBooNE detector at (or moving the existing
MiniBooNE detector to) a distance of ∼200 m from the Booster Neutrino
Beam (BNB) production target. With identical detectors at different distances,
most of the systematic errors will cancel when taking a ratio of events in the
two detectors, as the neutrino flux varies as 1/r2 to a calculable
approximation. This will allow sensitive tests of oscillations for both νe
and νˉe appearance and νμ and νˉμ disappearance.
Furthermore, a comparison between oscillations in neutrino mode and
antineutrino mode will allow a sensitive search for CP and CPT violation in the
lepton sector at short baseline (Δm2>0.1 eV2).Comment: 43 pages, 40 figure