Time Evolution of Lepton Number Carried by Majorana Neutrinos
Apriadi Salim Adam, Nicholas J. Benoit, Yuta Kawamura, Yamato Matsuo,, Takuya Morozumi, Yusuke Shimizu, Yuya Tokunaga, and Naoya Toyota

TL;DR
This paper investigates how lepton family numbers evolve over time for neutrinos with Majorana mass, highlighting their sensitivity to neutrino properties like phases, mass, and hierarchy, especially in the nonrelativistic regime relevant to cosmic background neutrinos.
Contribution
It provides a detailed analysis of lepton number evolution for Majorana neutrinos, including relativistic and nonrelativistic cases, and explores implications for cosmic neutrino background.
Findings
Lepton family numbers evolve distinctly for relativistic and nonrelativistic neutrinos.
Nonrelativistic lepton numbers are sensitive to Majorana and Dirac phases.
Results have implications for understanding cosmic neutrino background properties.
Abstract
We revisit the time evolution of the lepton family number for a SU(2) doublet consisting of a neutrino and a charged lepton. The lepton family number is defined through the weak basis of the SU(2) doublet, where the charged lepton mass matrix is real and diagonal. The lepton family number carried by the neutrino is defined by the left-handed current of the neutrino family. For this work we assume the neutrinos have Majorana mass. This Majorana mass term is switched on at time and the lepton family number is evolved. Since the operator in the flavor eigenstate is continuously connected to that of the mass eigenstate, the creation and annihilation operators for the two eigenstates are related to each other. We compute the time evolution of all lepton family numbers by choosing a specific initial flavor eigenstate for a neutrino. The evolution is studied for relativistic and…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
