2017/11/08 by M. Drewes, B. Garbrecht, P. Hernandez +7 · 1 citation
Physics and Astronomy · #Asymmetry #Dark Matter and Cosmic Phenomena #Electroweak interaction #Electroweak scale #Hamiltonian (control theory) #Leptogenesis #Mixing (physics) #Neutrino #Neutrino Physics Research #Parameter space #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1142/s0217751x18420022
46 pages, 8 figures. Chapter 2 of the review volume: Leptogenesis: Current Challenges for Model Building, Phenomenology and Non-Equilibrium Field Theory
arxiv created 2017/11/08 · openalex created_date 2017/12/22 · openalex publication_date 2018/02/28 · arxiv updated 2018/04/04 · openalex updated_date 2026/08/05
We review the current status of the leptogenesis scenario originally proposed by Akhmedov, Rubakov and Smirnov (ARS). It takes place in the parametric regime where the right-handed neutrinos are at the electroweak scale or below and the CP-violating effects are induced by the coherent superposition of different right-handed mass eigenstates. Two main theoretical approaches to derive quantum kinetic equations, the Hamiltonian time evolution as well as the Closed-Time-Path technique are presented, and we discuss their relations. For scenarios with two right-handed neutrinos, we chart the viable parameter space. Both, a Bayesian analysis, that determines the most likely configurations for viable leptogenesis given different variants of flat priors, and a determination of the maximally allowed mixing between the light, mostly left-handed, and heavy, mostly right-handed, neutrino states are discussed. Rephasing invariants are shown to be a useful tool to classify and to understand various distinct contributions to ARS leptogenesis that can dominate in different parametric regimes. While these analyses are carried out for the parametric regime where initial asymmetries are generated predominantly from lepton-number conserving, but flavor violating effects, we also review the contributions from lepton-number violating operators and identify the regions of parameter space where these are relevant.