5 research outputs found
Flavor and chiral oscillations with Dirac wave packets
We report about recent results on Dirac wave packets in the treatment of
neutrino flavor oscillation where the initial localization of a spinor state
implies an interference between positive and negative energy components of
mass-eigenstate wave packets. A satisfactory description of fermionic particles
requires the use of the Dirac equation as evolution equation for the
mass-eigenstates. In this context, a new flavor conversion formula can be
obtained when the effects of chiral oscillation are taken into account. Our
study leads to the conclusion that the fermionic nature of the particles, where
chiral oscillations and the interference between positive and negative
frequency components of mass-eigenstate wave packets are implicitly assumed,
modifies the standard oscillation probability. Nevertheless, for
ultra-relativistic particles and sharply peaked momentum distributions, we can
analytically demonstrate that these modifications introduce correction factors
proportional to (m12/p0) square which are practically un-detectable by any
experimental analysisComment: 16 pages, 2 figure
Dynamics of chiral oscillations - A comparative analysis with spin-flipping
Chiral oscillation as well as spin flipping effects correspond to quantum
phenomena of fundamental importance in the context of particle physics and, in
particular, of neutrino physics. From the point of view of first quantized
theories, we are specifically interested in appointing the differences between
chirality and helicity by obtaining their dynamic equations for a fermionic
Dirac-type particle (neutrino). We also identify both effects when the
non-minimal coupling with an external (electro)magnetic field in the neutrino
interacting Lagrangian is taken into account. We demonstrate that, however,
there is no constraint between chiral oscillations, when it takes place in
vacuum, and the process of spin flipping related to the helicity quantum
number, which does not take place in vacuum. To conclude, we show that the
origin of chiral oscillations (in vacuum) can be interpreted as position very
rapid oscillation projections onto the longitudinal direction of momentum.Comment: 14 pages, no figure
The construction of Dirac wave packets for a fermionic particle non-minimally coupling with an external magnetic field
We shall proceed with the construction of normalizable Dirac wave packets for
{\em fermionic} particles (neutrinos) with dynamics governed by a ``modified''
Dirac equation with a non-minimal coupling with an external magnetic field. We
are not only interested on the analytic solutions of the ``modified'' Dirac
wave equation but also on the construction of Dirac wave packets which can be
used for describing the dynamics of some observable physical quantities which
are relevant in the context of the quantum oscillation phenomena. To conclude,
we discuss qualitatively the applicability of this formal construction in the
treatment of chiral (and flavor) oscillations in the theoretical context of
neutrino physics.Comment: 10 page