Rapidity dependence of elliptic and triangular flow in proton-nucleus collisions from collective dynamics

The rapidity dependence of elliptic, $v_2$, and triangular, $v_3$, flow coefficients in proton-nucleus (p+A) collisions is predicted in hydrodynamics and in a multi-phase transport model (AMPT). We find that $v_n$ ($n=2,3$) on a nucleus side is significantly larger than on a proton side and the ratio between the two, $v_n^{\mathrm{P}\mathrm{b}}\mathrm{/}{v}_n^{\mathrm{p}}$, weekly depends on the transverse momentum of produced particles.