Correlation femtoscopy of heavy ion collisions

Full text: The momentum correlations of two or more particles at small relative momenta in their center-of-mass system are widely used to study space-time characteristics of the production processes on a level of fm 10-15 m, so serving as a correlation femtoscopy tool. Particularly, for non-interacting identical particles, like photons or, to some extent, pions, these correlations result from the interference of the production amplitudes due to the symmetrization requirement of quantum statistics. The momentum correlations of particles emitted at nuclear distances are also influenced by the effect of final state interaction (FSI). Thus the effect of the Coulomb interaction dominates the correlations of charged particles at very small relative momenta (of the order of the inverse Bohr radius of the two-particle system), respectively suppressing or enhancing the production of particles with like or unlike charges. Though the FSI effect complicates the correlation analysis, it is an important source of information allowing for the coalescence femtoscopy, the correlation femtoscopy with unlike particles including the access to the relative space-time asymmetries in particle production and a study of strong interactions between specific particles. In this review, I will shortly discuss the recent results obtained from the femtoscopy analysis of like and unlike particle correlations in relativistic heavy ion collisions. (author)