2014/07/31 by Mattias Blennow, Pilar Coloma, Enrique Fernandez-Martinez
Physics and Astronomy · #CP violation #Calibration #Monte Carlo method #Neutrino #Neutrino Physics Research #Particle physics theoretical and experimental studies #Radioactive Decay and Measurement Techniques #Sensitivity (control systems) #Sign (mathematics) #Standard Model (mathematical formulation) #Statistic #Test statistic #hep-ex #hep-ph
paper · pdf · doi:10.1007/jhep03(2015)005
14 pages, 5 figures, RevTeX4. The discussion of the results has been improved and considerably extended. Version accepted for publication in JHEP
arxiv created 2015/02/01 · openalex publication_date 2015/03/01 · arxiv updated 2015/06/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We address the validity of the usual procedure to determine the sensitivity of neutrino oscillation experiments to CP violation. An explicit calibration of the test statistic is performed through Monte Carlo simulations for several experimental setups. We find that significant deviations from a χ 2 distribution with one degree of freedom occur for experimental setups with low sensitivity to δ. In particular, when the allowed region to which δ is constrained at a given confidence level is comparable to the whole allowed range, the cyclic nature of the variable manifests and the premises of Wilk’s theorem are violated. This leads to values of the test statistic significantly lower than a χ 2 distribution at that confidence level. On the other hand, for facilities which can place better constraints on δ the cyclic nature of the variable is hidden and, as the potential of the facility improves, the values of the test statistics first become slightly higher than and then approach asymptotically a χ 2 distribution. The role of sign degeneracies is also discussed.