  A theoretical investigation on the coherent Dirac-like quasiparticle dynamics
in monolayer $\text{MoS}_2$ under an ultrashort optical pulse irradiation is
presented. Particularly, we remain specific features of ML-MDS associated with
the mass asymmetry $\alpha$ and topological aspect $\beta$ parameters resulting
in Schr$\stackrel{..}{\text{o}}$dinger type wavevector of charge carriers. The
direct band gap, spin-resolved valence band spilitting and valley degeneracy
breaking due to strong spin-orbit coupling affect ultrafast dynamics of Dirac
fermions. Because the duration of the optical pulse is less than the electron
scattering time, which is $\sim 10-100\ fs$, the electron dynamics in electric
field of the optical pulse is coherent, and consequently, we can describe the
coupling of electron with strong electromagnetic field by the time-dependent
Schr$\stackrel{..}{\text{o}}$dinger equation. The conduction band and valence
band coupling via the strong electric field of pulse ($0.2-2.5 \ V/\text{\AA}$)
gives rise to appearance of a dipole moment during the pulse is applied. We
find that the dipole is complex, originating from the existence of band gap. We
show an asymmetric singularities in Dirac points for absolute of dipole moment.
We solve the resulting coupled evolution equations for the expansion
coefficient of valence and conduction bands to obtain probability of population
transition between valence and conduction bands. The irreversible electron
dynamics as a key feature of two-dimensional Dirac matters in interacting with
an ultrashort pulse strongly depends on the electronic structure of
$\text{MoS}_2$. Furthermore, we present conduction band population distribution
with an asymmetric exhibition at the each pair of Dirac points ($K$ and $K'$),
when the pulse ends. This leads to valley polarization effect.
