8,384 research outputs found
Freeze-in Dirac neutrinogenesis: thermal leptonic CP asymmetry
We present a freeze-in realization of the Dirac neutrinogenesis in which the
decaying particle that generates the lepton-number asymmetry is in thermal
equilibrium. As the right-handed Dirac neutrinos are produced non-thermally,
the lepton-number asymmetry is accumulated and partially converted to the
baryon-number asymmetry via the rapid sphaleron transitions. The necessary
CP-violating condition can be fulfilled by a purely thermal kinetic phase from
the wavefunction correction in the lepton-doublet sector, which has been
neglected in most leptogenesis-based setup. Furthermore, this condition
necessitates a preferred flavor basis in which both the charged-lepton and
neutrino Yukawa matrices are non-diagonal. To protect such a proper Yukawa
structure from the basis transformations in flavor space prior to the
electroweak gauge symmetry breaking, we can resort to a plethora of model
buildings aimed at deciphering the non-trivial Yukawa structures.
Interestingly, based on the well-known tri-bimaximal mixing with a minimal
correction from the charged-lepton or neutrino sector, we find that a
simultaneous explanation of the baryon-number asymmetry in the Universe and the
low-energy neutrino oscillation observables can be attributed to the mixing
angle and the CP-violating phase introduced in the minimal correction.Comment: 28 pages and 7 figures; more discussions and one figure added, final
version published in the journa
Separation of Phytosterol and Synthesized VE Succinate from Rapeseed Oil Deodorizer Distillate
Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 7 (2005): Separation of Phytosterol and Synthesized VE Succinate from Rapeseed Oil Deodorizer Distillate by Pan Li-jun, Shao Ping, Jiang Shao-ton
Studying newborn neutron stars by the transient emission after stellar collapses and compact binary mergers
The formation of neutron stars (NSs), both from collapses of massive stars
and mergers of compact objects, can be usually indicated by bright transients
emitted from explosively-ejected material. In particular, if the newborn NSs
can rotate at a millisecond period and have a sufficiently high magnetic field,
then the spin-down of the NSs would provide a remarkable amount of energy to
the emitting material. As a result, super-luminous supernovae could be produced
in the massive stellar collapse cases, while some unusual fast evolving and
luminous optical transients could arise from the cases of NS mergers and
accretion-induced collapses of white dwarfs. In all cases, if the dipolar
magnetic fields of the newborn NSs can be amplified to be as high as
G, a relativistic jet could be launched and then a gamma-ray burst can be
produced as the jet successfully breaks out from the surrounding
nearly-isotropic ejected material.Comment: 10 pages, 9 pictures, to appear in the AIP Proceedings of the
Xiamen-CUSTIPEN Workshop on the EOS of Dense Neutron-Rich Matter in the Era
of Gravitational Wave Astronomy, Jan. 3-7, Xiamen, Chin
Quantum Transport from the Perspective of Quantum Open Systems
By viewing the non-equilibrium transport setup as a quantum open system, we
propose a reduced-density-matrix based quantum transport formalism. At the
level of self-consistent Born approximation, it can precisely account for the
correlation between tunneling and the system internal many-body interaction,
leading to certain novel behavior such as the non-equilibrium Kondo effect. It
also opens a new way to construct time-dependent density functional theory for
transport through large-scale complex systems.Comment: 4 pages, 2 figures; the TDDFT scheme is explained in more detail in
this new versio
- …
