Baryogenesis from hierarchical Dirac neutrinos

作者:Li, Shao-Ping*; Li, Xin-Qiang; Yan, Xin-Shuai; Yang, Ya-Dong
来源:Physical Review D, 2021, 104(11): 115014.
DOI:10.1103/PhysRevD.104.115014

摘要

We present here a novel and testable mechanism for leptogenesis, which is characterized by a purely thermal generation of lepton asymmetry via scalar decay. Guided by the thermal mass matrix diagonalization in the finite-temperature regime, we propose a scenario in which the baryon asymmetry is formulated in terms of the masses and mixing from hierarchical Dirac neutrinos, as well as a vacuum scale accountable for the sub-eV neutrino masses. This allows a natural and direct link between the highscale CP asymmetry and the low-energy Dirac CP-violating phase without involved model structures, and thus circumvents the haunting problem encountered in general leptogenesis scenarios. The mechanism can also be applied as a prototype for solving the baryon asymmetry problem to a broad class of well-motivated model buildings.