  By considering three different Nucleon-Nucleon (NN) elastic differential
cross sections: the Cugnon \emph{et al.} parameterized differential cross
section [Nucl. Instrum. Methods Phys. Res., Sect. \textbf{B111}, 215 (1996)],
and the differential cross section derived from the collision term of the
self-consistent relativistic Boltzmann-Uehling-Uhlenbeck equation proposed by
Mao \emph{et al.} [Z.\ Phys.\ A {\bf 347}, 173 (1994)], as well as the
isotropic differential cross section, within the newly updated version of the
ultrarelativistic quantum molecular dynamics (UrQMD) model, the influence of
the differential elastic NN cross section on various observables (e.g., nuclear
stopping, both the rapidity and transverse-velocity dependence of the directed
and elliptic flows) in Au+Au collisions at beam energies 150, 250, 400, and 800
MeV$/$nucleon is investigated. By comparing calculations with those three
differential cross sections, it is found that the nuclear stopping power, the
directed and elliptic flows are affected to some extent by the differential
cross sections, and the impact of differential cross section on those
observables becomes more visible as the beam energy increases. The effect on
the elliptic flow difference $v_{2}^{n}$-$v_{2}^{H}$ and ratio
$v_{2}^{n}$/$v_{2}^{H}$ of neutrons versus hydrogen isotopes ($Z=1$), which
have been used as sensitive observables for probing nuclear symmetry energy at
high densities, is weak.
