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

A A Aguilar-Arevalo ,C Mauger,P Spentzouris,L Bugel,T Kobilarcik,J Monroe,A Curioni,C Green,D Schmitz,Z Djurcic,L Coney,S Ouedraogo,W Metcalf,R Imlay,B Osmanov,S Koutsoliotas,I Kourbanis,D Smith,V Sandberg,R Schirato,J Mousseau,T Katori,D Perevalov,E Prebys,P Nienaber,M.H Shaevitz,M Tzanov,R Tayloe,G Mcgregor,G Karagiorgi,E Hawker,R Dharmapalan,M Soderberg,W Huelsnitz,H Ray,F Mills,W Marsh,R Ford,I Stancu,M Sung,Y Liu,J Spitz,J.A Green,M Sorel,J M Link ,V T Mcgary ,G B Mills ,W C Louis ,J M Conrad ,Robert H Nelson ,Bruce Brown ,M J Wilking ,G P Zeller ,A O Bazarko ,T Hart ,Kendall Mahn ,R A Johnson ,J Nowak ,Carl E Anderson ,Ž Pavlović ,C D Moore ,B P Roe ,D C Cox ,J L Raaf ,F C Shoemaker ,F García ,E Laird ,S J Brice ,H J Yang ,Hirohisa Tanaka ,P D Meyers ,R B Patterson ,P A Kasper ,Joseph Grange ,A D Russell ,S K Linden ,M O Wascko ,D A Finley ,R G Van De Water ,D H White ,C C Polly ,R J Stefanski ,Junpeng Cao ,B T Fleming ,G T Garvey ,E D Zimmerman

doi:10.1016/j.physletb.2012.12.020

Abstract

The sidereal time dependence of MiniBooNE νe 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 νe 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 νe 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 νμ→νe and ν¯μ→ν¯e oscillations. The fit values and limits of combinations of SME coefficients are provided.

Highlights

Introduction of Loremtz violationViolation of Lorentz invariance and CPT symmetry is a predicted phenomenon of Planck scale physics, especially with a spontaneous violation [1], and it does not require any modifications in quantum field theory or general relativity
We evaluate the impact of this variation on our analysis by correcting protons on target (POT) variation event by event in νe candidate data
The sidereal time distributions tend to show lower compatibility with a flat hypothesis, but not by a statistically significant amount. These results indicate that any sidereal variation extracted from our data, discussed below, is not expected to be statistically significant

Summary

Introduction of Loremtz violation

Violation of Lorentz invariance and CPT symmetry is a predicted phenomenon of Planck scale physics, especially with a spontaneous violation [1], and it does not require any modifications in quantum field theory or general relativity. Since neutrino oscillation experiments are natural interferometers, they can serve as sensitive probes of space-time structure. Neutrino oscillations have the potential to provide the first experimental evidence for Lorentz and CPT violation through evidence of oscillations that deviate from the standard L/E dependence [2], or that show sidereal time dependent oscillations as a consequence of a preferred direction in the universe [3]. Some Lorentz violating neutrino oscillation models mimic the standard massive neutrino oscillation energy dependence [9]. In this case, the signal may only be seen in sidereal variations of oscillation experiments

MiniBooNE experiment

Analysis

Results