Pion Femtoscopy in p/d plus Au Collisions at vsNN=200 GeV in the STAR Experiment

It is interesting to see how the space-time characteristics of the region of particle emission created during nuclear collisions change as the colliding nuclei get bigger. At an energy of 200 GeV per nucleon pair, the STAR experiment allows one to investigate the properties of the created medium for two colliding systems with nearly identical sizes: p + Au and d + Au. As a result, the difference in particle emission region properties introduced by just one more nucleon may be detected. Using the femtoscopy technique it becomes possible to perform this measurement. The paper investigates the dependence of the emission region's invariant radii on the transverse momentum of pion pairs for various multiplicities in the p + Au and d + Au collision systems. The physical implication is also presented in this paper.