Looking for Leptonic CP Violation with Neutrinos

TL;DR

This paper explores theoretical methods to observe leptonic CP violation, focusing on Majorana and KM phases, and discusses experimental setups like the Tokai-to-Kamioka-Korea project for detecting CP violation and resolving neutrino mass hierarchy.

Contribution

It provides a detailed analysis of how to detect leptonic CP violation through neutrinoless double beta decay and neutrino oscillation experiments, including specific experimental proposals.

Findings

Estimated the impact of Majorana phases on neutrinoless double beta decay observables.

Discussed the potential of the Tokai-to-Kamioka-Korea experiment to discover CP violation.

Provided cautionary insights on comparing different experimental projects.

Abstract

I discuss some theoretical aspects of how to observe leptonic CP violation. It is divided into two parts, one for CP violation due to Majorana, and the other more conventional leptonic Kobayashi-Maskawa (KM) phases. In the first part, I estimate the effect of Majorana phase to observable of neutrinoless double beta decay experiments by paying a careful attention to the definition of the atmospheric scale Delta m^2. In the second part, I discuss Tokai-to-Kamioka-Korea two detector complex which receives neutrino superbeam from J-PARC as a concrete setting for discovering CP violation due to the KM phase, as well as resolving mass hierarchy and the theta_{23} octant degeneracy. A cautionary remark is also given on comparison between various projects aiming at exploring CP violation and the mass hierarchy.