2001/02/06 by H. Schlattl, Helmut Schlattl
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Neutrino Physics Research #Particle physics theoretical and experimental studies #astro-ph #hep-ph
paper · pdf · doi:10.1103/physrevd.64.013009
published as Phys.Rev. D64 (2001) 013009 · 22 pages, 19 figures, REVTeX, submitted to Phys.Rev.D, article with better resolved figures available under http://www.mpa-garching.mpg.de/~schlattl/public.html
arxiv created 2001/02/06 · openalex publication_date 2001/06/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The good agreement of standard solar models with helioseismology and the combined analysis of the solar neutrino experiments suggest that the solution of the solar neutrino problem is located in particle physics rather than in astrophysics. The most promising solution is neutrino oscillations, which usually are analyzed within the reduced two-flavor scheme, because the solutions found therein reasonably well reproduce the recent data of Super-Kamiokande about the recoil-electron energy spectrum, zenith-angle and seasonal variations, and the event rate data of all the neutrino detectors. In this work, however, a survey of the complete parameter space of three-flavor oscillations is performed. Basically 8 three-flavor solutions could be identified, where the best one with \ensuremathΔm122=2.7\ifmmode×\else\texttimes\fi10^\ensuremath-10 eV2, \ensuremathΔm132=1.0\ifmmode×\else\texttimes\fi10^\ensuremath-5 eV2, \ensuremathΘ12=23\ifmmode^∘\else\textdegree\fi, and \ensuremathΘ13=1.3\ifmmode^∘\else\textdegree\fi (denoted SVO) is slightly more probable than any two-flavor solution. However, as the greatest value for \ensuremathΔm232 of these three-flavor solutions is about 2.5\ifmmode×\else\texttimes\fi10^\ensuremath-4 eV2, none of these solutions is consistent with the results of the atmospheric neutrino problem where \ensuremathΔm232\ensuremath\gtrsim10^\ensuremath-3 eV2. The relatively weak improvement of the fit using three-flavor instead of two-flavor oscillations, which appears to be due to an inconsistency of the different kinds of data, indicates that there are possibly still systematic errors in at least one data set or that the statistics is not yet sufficient. In addition, the abilities of SNO and Borexino to discriminate the various two- and three-flavor solutions are investigated. Only with very good statistics in these experiments can the correct solution to the solar neutrino problem be identified unambiguously.