MINOS and CPT violating neutrinos

We review the status of CPT violation in the neutrino sector. Apart from LSND, current data favors three flavors of light stable neutrinos and antineutrinos, with both halves of the spectrum having one smaller mass splitting and one larger mass splitting. Oscillation data for the smaller splitting are consistent with CPT. For the larger splitting, current data favor an antineutrino mass-squared splitting that is an order of magnitude larger than the corresponding neutrino splitting, with the corresponding mixing angle less than maximal. This CPT-violating spectrum is driven by recent results from MINOS, but is consistent with other experiments if we ignore LSND. We describe an analysis technique which, together with MINOS running optimized for muon antineutrinos, should be able to conclusively confirm the CPT-violating spectrum proposed here, with as little as 3 times the current data set. If confirmed, the CPT-violating neutrino mass-squared difference would be an order of magnitude less than the current most-stringent upper bound on CPT violation for quarks and charged leptons.The authors are grateful to Milind Diwan, Georgia Karagiorgi, Bill Louis, Olga Mena, Maurizio Pierini, Chris Quigg, and Chris Rogan. for useful discussions. GB acknowledges support from the Spanish MEC and FEDER under Contract FPA 2008/02878, and a Prometo grant. Fermilab is operated by the Fermi Research Alliance LLC under contact DE-AC02-07CH11359 with the U.S. Dept. of Energy.Peer reviewe