A close look on 2-3 mixing angle with DUNE in light of current neutrino oscillation

 

This paper focuses on three major issues

• deviation of atmospheric mixing angle from maximal mixing (MM)
• precision measurement in atmospheric parameters
• issue of octant degeneracy

using the current best-fit parameters given by Capozzi et al. in DUNE considering recent collaboration updates. They find that given the true mass ordering fixed to normal, other oscillation parameters fixed to best-fit values by Capozzi et al., DUNE can establish a deviation from MM with a 4.2σ (5σ) C.L. in 7 (10) years of equally divided exposure. They also find the importance of spectral distribution in removing degeneracies among atmospheric parameters in the disappearance channel. They quote that both neutrino and antineutrino modes are essential for ruling out solutions in the wrong octant. They find that DUNE can resolve the issue of octant degeneracy with 3.5σ (4.1σ) sigma C.L. in 7 (10) years of equally divided exposure. DUNE can improve the current relative 1σ precision on atmospheric mixing angle (atmospheric mass-splitting) by a factor of 4.4σ (2.8σ) using 7 years of exposure. They also provide the range of θ23 vs the exposure figure which gives a range of θ23 beyond which, DUNE will be able to establish a deviation from maximal θ23 . Below is one of the figures from the paper which gives an overview of the scenario in DUNE to establish non-maximal θ23 for 7 years of exposure.