Second octant favored for non-maximal 𝜃23

Abstract

One of the most robust relationships predicted by binary tetrahedral [Formula: see text] flavor symmetry relates the reactor neutrino angle [Formula: see text] to the atmospheric neutrino angle [Formula: see text], independently of [Formula: see text]. It has the form [Formula: see text]. When this prediction first appeared in 2008, [Formula: see text] was consistent with zero and [Formula: see text] with [Formula: see text]. Nonzero [Formula: see text] was established by Daya Bay in 2012. Nonzero [Formula: see text] is now favored by the NO[Formula: see text]A experiment and, for [Formula: see text], the aforementioned [Formula: see text] relation selects the second octant [Formula: see text] over the first octant [Formula: see text]. This analysis initially assumes CP conservation in the lepton sector, but leptonic CP violation is discussed and it is shown that this specific [Formula: see text] relationship is invariant.