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

Abstract

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.