Uncovering Majorana nature through a precision measurement of $CP$ phase

TL;DR

This paper proposes a method to detect the Majorana nature of neutrinos by measuring the Majorana CP phase at DUNE, highlighting the impact of decoherence effects and comparing with T2HK and T2K results.

Contribution

It introduces a novel approach to uncover neutrino Majorana nature through precision measurement of the CP phase considering decoherence effects at DUNE.

Findings

Decoherence causes measurable distortion in Dirac CP phase measurements.

DUNE can measure the Majorana phase with about 21-23% precision under certain decoherence conditions.

The precision at DUNE is comparable to current T2K measurements for the Dirac CP phase.

Abstract

We show the possibility to discover the neutrino nature by measuring the Majorana CP phase at the DUNE experiment. This phase is turned on by a decoherence environment, possibly originated by physics at the Planck scale. A sizable distortion in the measurement of the Dirac CP violation phase $\delta_{\mathrm{CP}}$ is observed at DUNE when compared with T2HK measurement due to decoherence and non-null Majorana phase. Being that, when the measurement of the Majorana phase is performed at DUNE, it reaches a precision of 23 (21) $\%$ for a decoherence parameter $\Gamma=4.5(5.5)\times 10^{-24} \mathrm{GeV}$ and a Majorana phase equal to $1.5 \pi$. The latter precision is similar to the one obtained at the T2K experiment at its current Dirac CP violation phase measurement.