2008/04/30 by Abhijit Bandyopadhyay, Sandhya Choubey, Bandyopadhyay, Abhijit +8 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ex #hep-ph
paper · pdf · doi:10.48550/arxiv.0804.4857
15 pages, 5 figures
arxiv created 2008/04/30 · openalex publication_date 2008/04/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We do a re-analysis to asses the impact of the results of the Borexino experiment and the recent 2.8 KTy KamLAND data on the solar neutrino oscillation parameters. The current Borexino results are found to have no impact on the allowed solar neutrino parameter space. The new KamLAND data causes a significant reduction of the allowed range of Δm221, determining it with an unprecedented precision of 8.3% at 3σ. The precision of Δm221 is controlled practically by the KamLAND data alone. Inclusion of new KamLAND results also improves the upper bound on sin2θ12, but the precision of this parameter continues to be controlled by the solar data. The third mixing angle is constrained to be sin2θ13 < 0.063 at 3σ from a combined fit to the solar, KamLAND, atmospheric and CHOOZ results. We also address the issue of how much further reduction of allowed range of Δm221 and sin2θ12 is possible with increased statistics from KamLAND. We find that there is a sharp reduction of the 3σ ``spread'' with enhanced statistics till about 10 KTy after which the spread tends to flatten out reaching to less than 4% with 15 KTy data. For sin2θ12 however, the spread is more than 25% even after 20 KTy exposure and assuming θ12 < π/4, as dictated by the solar data. We show that with a KamLAND like reactor ``SPMIN'' experiment at a distance of ∼ 60 km, the spread of sin2θ12 could be reduced to about 5% at 3σ level while Δm212 could be determined to within 4%, with just 3 KTy exposure.