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

Abstract The sidereal time dependence of MiniBooNE ν e and ν ¯ 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 e and ν ¯ 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 e appearance data prefer a sidereal time-independent solution, and the ν ¯ e appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10 − 20 GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for ν μ → ν e and ν ¯ μ → ν ¯ e oscillations. The fit values and limits of combinations of SME coefficients are provided.