Before and After: How has the SNO NC measurement changed things?

John N Bahcall, Concepción M Gonzalez-Garcia, Carlos Pena-Garay
2002 Journal of High Energy Physics  
We present "Before and After" global oscillation solutions, as well as predicted "Before and After" values and ranges for ten future solar neutrino observables (for BOREXINO, KamLAND, SNO, and a generic p-p neutrino detector). We have performed global analyses using the full SNO day-night energy spectrum and, alternatively, just the SNO CC and NC rates and the day-night asymmetry.The "Before" case includes all solar neutrino data (and some theoretical improvements) available prior to April 20,
more » ... prior to April 20, 2002 and the "After" case includes, in addition, the new SNO data on the CC, NC, and day-night asymmetry. The LMA solution is the only currently allowed MSW oscillation solution at ~99% CL. The LOW solution is allowed only at more than 2.5 sigma, SMA at 3.7 sigma or 4.7 sigma (depending upon analysis strategy), and pure sterile oscillations at 4.7sigma. Small mixing angles are "out"(pure sterile is "way out"); MSW with large mixing angles is definitely "in". Vacuum oscillations are allowed at 3 sigma, but not a 2 sigma. Precise maximal mixing is excluded at 3.2 sigma for MSW solutions and at 2.8 sigma for vacuum solutions. Most of the predicted values for future observables for the BOREXINO, KamLAND, and future SNO measurements are changed only by minor amounts by the inclusion of the recent SNO data. In order to test the robustness of the allowed neutrino oscillation regions and the predictions for future observables, we have carried out calculations using a variety of strategies to analyze the SNO and other solar neutrino data.
doi:10.1088/1126-6708/2002/07/054 fatcat:vprpojmrjrfjdb756g56ar3qse