Abstract
The elliptic ($v_2$) and triangular ($v_3$) azimuthal anisotropy coefficients
in central $^{3}$He+Au, $d$+Au, and $p$+Au collisions at
$\mbox{$\sqrt{s_{\mathrm{NN}}}$}$ = 200 GeV are measured as a function of
transverse momentum ($p_{\mathrm{T}}$) at mid-rapidity ($|\eta|<$0.9), via the
azimuthal angular correlation between two particles both at $|\eta|<$0.9. While
the $v_2(p_{\mathrm{T}})$ values depend on the colliding systems, the
$v_3(p_{\mathrm{T}})$ values are system-independent within the uncertainties,
suggesting an influence on eccentricity from sub-nucleonic fluctuations in
these small-sized systems. These results also provide stringent constraints for
the hydrodynamic modeling of these systems.