O+O at RHIC

Nucleon force and emergent nucleon correlations, such as alpha clustering, play a fundamental role in the structure of light atomic nuclei. High-energy light-ion collisions at RHIC and the LHC, such as $^{16}$O+$^{16}$O, d+Au and $^{3}$He+Au, provide a new tool for understanding this physics. These structural effects impact the initial state of these collisions and leave a footprint in flow correlations among final state particles. We present measurements of elliptic and triangular flow ($v_2$ and $v_3$) obtained from multi-particle correlations in O+O, d+Au and $^{3}$He+Au collisions at 200 GeV. The results are compared with two state-of-the-art \textit{ab initio} calculations for $^{16}$O: the NLEFT and VMC model. We found significant model dependence in the predicted flow signals. Hence our results provide strong discriminatory power to the structure of the light nuclei.