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.
Before introducing Dirac wave packets, we review the scalar prescription
for flavor oscillation in an extended analytic study where slippage and
spreading effects are quantified.
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
articles, 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 m_1,2**{2}/p_0**2
which are practically un-detectable by any experimental analysis.