Testing CPT Invariance with Neutrinos

We investigate possible tests of CPT invariance on the level of event rates at neutrino factories. We do not assume any specific model, but phenomenological differences in the neutrino-antineutrino masses and mixing angles in a Lorentz invariance preserving context, which could be induced by physics beyond the Standard Model. We especially focus on the muon neutrino and antineutrino disappearance channels in order to obtain constraints on the neutrino-antineutrino mass and mixing angle differences. In a typical neutrino factory setup simulation, we find, for example, that $|m_3 - \bar{m}_3| \lesssim 1.9 \cdot 10^{-4} \mathrm{eV}$ and $|\theta_{23} -\bar \theta_{23}| \lesssim 2^\circ$.