Test of Lorentz and CPT violation with short baseline neutrino oscillation excesses

The sidereal time dependence of MiniBooNE ν[subscript e] and ν[over-bar][subscript e] appearance data is analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov–Smirnov (K–S) test shows both the ν[subscript e] and ν[over-bar][subscript e] appearance data are compatible with the null sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit with a Lorentz-violating oscillation model derived from the Standard Model Extension (SME) to describe any excess events over background, we find that the ν[subscript e] appearance data prefer a sidereal time-independent solution, and the ν[over-bar][subscript e] appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10−20 GeV10−20 GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for ν[subscript μ] →ν[subscript e] and ν[over-bar][subscript μ]→ν[over-bar][subscript e] oscillations. The fit values and limits of combinations of SME coefficients are provided.
Fermi National Accelerator Laboratory
United States. Dept. of Energy
National Science Foundation (U.S.)
Indiana University, Bloomington. Center for Spacetime Symmetries