Azimuthally-Differential Two-Pion Femtoscopy in Zr + Zr and Ru + Ru Collisions at $$\sqrt {{{s}_{{NN}}}} = 200$$ GeV Using the UrQMD Model

Correlation femtoscopy allows one to estimate the spatial and temporal characteristics of the particle-emitting region formed in the relativistic heavy-ion collisions. Azimuthally-differential analysis is used to study shape and orientation of the source. In this work, collisions of isobaric nuclei Ru + Ru and Zr + Zr at $$\sqrt {{{s}_{{NN}}}} = 200$$ GeV are calculated using the UrQMD (Ultrarelativistic Quantum Molecular Dynamics) model and the azimuthally-differential two-pion femtoscopy relative to the second- and third-order event plane are performed. The extracted characteristics of the emission source are presented as a function of the pair transverse momentum, $${{k}_{T}}$$ , collision centrality and the pair emission angle. In the future, the obtained results can be compared with the STAR experimental data.