From oscillation dip to oscillation valley in atmospheric neutrino experiments
Presented at The XXIX International Conference on Neutrino Physics and Astrophysics (Neutrino 2020), 2020
Conference: The XXIX International Conference on Neutrino Physics and Astrophysics (Neutrino 2020), Online
Presentation mode: Online
Abstract: Atmospheric neutrino experiments can show the “oscillation dip” feature in data, due to their sensitivity over a large L/E range. In experiments that can distinguish between neutrinos and antineutrinos, like INO, oscillation dips can be observed in both these channels separately. We present a data-driven approach – that uses the asymmetry in the up and down events, binned in the reconstructed L/E of muons – to demonstrate the dip, thereby confirming the oscillation hypothesis. We further propose, for the first time, the identification of an “oscillation valley” in the (Eμ−cosθμ) plane, feasible for detectors like INO having excellent muon energy and direction resolutions. We illustrate how this two-dimensional valley offers a clear visual representation and test of the L/E dependence, the alignment of the valley quantifying the atmospheric mass-squared difference.