Reaction plane alignment with linearly polarized photon in heavy-ion collisions

The collective observables play critical roles in probing the properties of quark-gluon-plasma created in relativistic heavy-ion collisions, in which the information on initial collision geometry is crucial. However, the initial collision geometry, e.g., the reaction plane, cannot be directly extracted in the experiment. In this paper, we demonstrate the idea of determining the reaction plane via the feature of linear polarization of the coherent photoproduction process and discuss the advantages of the proposed approach in comparison with traditional methods.