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Three-flavour neutrino oscillation update and comments on possible hints for a non-zero theta_{13}

Authors :
Michele Maltoni
Thomas Schwetz
Source :
Digital.CSIC. Repositorio Institucional del CSIC, instname
Publication Year :
2008

Abstract

8 pages, 3 figures, 1 table.<br />We provide a short summary of three-flavour neutrino oscillation parameters as determined from a global fit to 2008 data, and we comment on possible hints in favour of a non-zero value of the mixing angle theta_{13} found in arXiv:0806.2649. We do confirm a hint from solar + KamLAND data at about 1.5 sigma, which can be understood from the recent SNO CC/NC measurment. However, we show that a claimed hint from atmospheric data is much less robust. It depends on details of event rate calculations and treatment of theoretical uncertainties. We could identify two data points showing an 'excess' (at the 1 sigma level) in the SK-I multi-GeV e-like data, which seem to be the origin of the slight preference for theta_{13} > 0. We point out that once SK-I and SK-II data are combined this 'excess' disappears, and irrespective of the details of the analysis, no 'hint' from atmospheric data is obtained for the SK-I and SK-II combined data set. As a result the global fit of all data leads to a best fit value of theta_{13} consistent with zero within less than 1 sigma.<br />TS is supported by the European Community-Research Infrastructure Activity under the FP6 “Structuring the European Research Area” program (CARE, contract number RII3-CT-2003-506395). MM is supported by MICINN through the Ramón y Cajal program and through the national project FPA2006-01105, and by the Comunidad Autónoma deMadrid through the HEPHACOS project P-ESP-00346. MM acknowledges the hospitality of The Abdus Salam ICTP where this work was completed.

Details

Language :
English
ISSN :
20035063
Database :
OpenAIRE
Journal :
Digital.CSIC. Repositorio Institucional del CSIC, instname
Accession number :
edsair.doi.dedup.....1c9172fe3cb8c9ea83d50e55bdbada8c