An open window to neutrino mass hierarchy at maximal Dirac CP violation

TL;DR

This paper explores how measuring CP asymmetry at specific experimental setups can simultaneously determine the neutrino mass hierarchy and the Dirac CP violation phase, especially at maximal CP violation, advancing neutrino physics understanding.

Contribution

It proposes a novel approach linking CP asymmetry measurements to neutrino mass hierarchy determination at maximal Dirac CP violation, within specific experimental conditions.

Findings

Neutrino mass hierarchy can be revealed at maximal CP violation with appropriate baseline and energy.

Parameter spaces exist where both mass hierarchy and CP violation can be determined simultaneously.

Current long baseline experiments have potential to address the neutrino mass hierarchy under these conditions.

Abstract

Non-zero leptonic CP phases in the neutrino sector are clear evidence for physics beyond the Standard Model and have many implications in particle physics and cosmology. Some clues to maximal Dirac CP violation $\delta_{CP}=3\pi/2$ are reviewed. An approach to connect the Dirac CP violation phase and the neutrino mass hierarchy in terms of the measurement of CP asymmetry is proposed. Under appropriate requirements for baseline distance and beam energy, the problem of neutrino mass hierarchy can be revealed at maximal Dirac CP violation. General allowed parameter spaces are investigated, within which the two unknown neutrino issues, mass hierarchy and Dirac CP violation, can be solved simultaneously. The abilities of addressing the mass hierarchy of current long baseline neutrino experiments are also discussed.