New CP violation in neutrino oscillations - art. no. 096006

Measurements of CP-violating observables in neutrino oscillation experiment s have been studied in the literature as a way to determine the CP-violatin g phase in the mixing matrix for leptons. Here we show that such observable s also probe new neutrino interactions in the production or detection proce sses. Genuine CP violation and fake CP violation due to matter effects are sensitive to the imaginary and real parts of new couplings. The dependence of the CP asymmetry on the source-detector distance is different from the s tandard one and, in particular, enhanced at short distances. We estimate th at future neutrino factories will be able to probe in this way new interact ions that are up to four orders of magnitude weaker than the weak interacti ons. We discuss the possible implications for models of new physics.