2013/03/19 by D. Delepine, D. Delépine, C. Lujan-Peschard +5
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.1303.4687
12 pages, 9 figures
arxiv created 2013/03/19 · openalex publication_date 2013/03/19 · arxiv updated 2013/03/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A general analysis of the consequences of including a fourth neutrino in the standard model matter content, on CP violating observables at neutrino oscillation experiments, is presented. Neutrino oscillations in vacuum and with matter effects are studied. For the former we update and generalize previous studies on CP asymmetries with an additional active neutrino using an updated fit of the PMNS mixing matrix. We study the values of the new CP violating phases which maximize the different CP asymmetries in T2K and MINOS-like setups aiming to elucidate if the new phases yield measurable effects in the most favorable case. We show that due to a combined effect of kinematics and unitarity it is possible to obtain an observable asymmetry in the survival channels without violating CPT. For the MINOS-like setup, we find maximum asymmetries in vacuum of the order of 2% and 4% for the νμ→ νe and νe → ντ channels respectively. For the T2K-like setup we obtain maximum asymmetries of the order of 6% in the survival νμ→ νμ channel. Tree level matter effects enhance the former reaching asymmetries of the order of 10% for the νμ→ νe and νe → ντ channels, while the νμ→ νμ survival channel changes slightly depending on the mass hierarchy. Box diagrams with the fourth mass eigenstate as a virtual particle were also considered, the corrections to the scattering amplitude being negligible.