Correlations of errors in measurements of CP violation at neutrino factories - art. no. 093008

Citation
J. Pinney et O. Yasuda, Correlations of errors in measurements of CP violation at neutrino factories - art. no. 093008, PHYS REV D, 6409(9), 2001, pp. 3008
Citations number
78
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW D
ISSN journal
0556-2821 → ACNP
Volume
6409
Issue
9
Year of publication
2001
Database
ISI
SICI code
0556-2821(20011101)6409:9<3008:COEIMO>2.0.ZU;2-T
Abstract
Using Delta chi (2) which is defined by the difference of the number of eve nts with the CP phase delta and the hypothetical one with delta =0, we disc uss correlations of errors of the CP phase and other oscillation parameters as well as the matter effect in measurements at neutrino factories. By var ying the oscillation parameters and the normalization of the matter effect, we evaluated the data size required to reject a hypothesis with delta =0 a t 3 sigma C.L. The optimum muon energy and the baseline depend on the magni tude of theta (13), the background fraction, and the uncertainty of the nor malization of the matter effect, but in general lie in the range 20 GeV les s than or similar to E-mu less than or similar to 50 GeV, 1000 km less than or similar to L less than or similar to 3000 km. If we assume that the unc ertainty of the matter effect is as large as 20% then the optimum values ma y be modified to E-mu less than or similar to 10 GeV, L less than or simila r to 1000 km due to the strong correlation of delta and the matter effect. We show analytically that sensitivity to CP violation is lost for E mu much less than 10 GeV or for E mu much greater than 50 GeV. We also discuss the possibility of measuring CP violation at the upgraded JHF experiment by ta king all the error correlations into account. and show that it is possible to demonstrate delta not equal0 at 3 sigma C.L. for theta (13) greater than or similar to 3 degrees.