The large value of θ13 recently measured by rector and accelerator experiments opens unprecedented opportunities for precision oscillation physics. In this paper, we reconsider the physics reach of medium baseline superbeams. For θ13≃9° we show that facilities at medium baselines-i.e. L ≃ O (1000 km)-remain optimal for the study of CP violation in the leptonic sector, although their ultimate precision strongly depends on experimental systematics. This is demonstrated in particular for facilities of practical interest in Europe: a CERN to Gran Sasso and CERN to Phyäsalmi νμ beam based on the present SPS and on new high power 50 GeV proton driver. Due to the large value of θ13, spectral information can be employed at medium baselines to resolve the sign ambiguity and determine the neutrino mass hierarchy. However, longer baselines, where matter effects dominate the νμ → νe transition, can achieve much stronger sensitivity to sign(Δ m2 even at moderate exposures. © 2013 Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica.
Dusini, S., Longhin, A., Mezzetto, M., Patrizi, L., Sioli, M., Sirri, G., et al. (2013). CP violation and mass hierarchy at medium baselines in the large theta(13) era. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 73(4), 1-9 [10.1140/epjc/s10052-013-2392-z].
CP violation and mass hierarchy at medium baselines in the large theta(13) era
TERRANOVA, FRANCESCO
2013
Abstract
The large value of θ13 recently measured by rector and accelerator experiments opens unprecedented opportunities for precision oscillation physics. In this paper, we reconsider the physics reach of medium baseline superbeams. For θ13≃9° we show that facilities at medium baselines-i.e. L ≃ O (1000 km)-remain optimal for the study of CP violation in the leptonic sector, although their ultimate precision strongly depends on experimental systematics. This is demonstrated in particular for facilities of practical interest in Europe: a CERN to Gran Sasso and CERN to Phyäsalmi νμ beam based on the present SPS and on new high power 50 GeV proton driver. Due to the large value of θ13, spectral information can be employed at medium baselines to resolve the sign ambiguity and determine the neutrino mass hierarchy. However, longer baselines, where matter effects dominate the νμ → νe transition, can achieve much stronger sensitivity to sign(Δ m2 even at moderate exposures. © 2013 Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.