Femtoscopy with unlike-sign kaons at STAR in 200 GeV Au+Au collisions

In the collisions of heavy ions the nuclear matter can undergo a phase transition from hadrons to a state of deconfined quarks and gluons called the Quak-Gluon Plasma. Femtoscopic measurements of two-particle correlations at small relative momenta reveal information about the space-time characteristics of the system at the moment of particle emission. The correlations result from quantum statistics, final-state Coulomb interactions, and the strong final-state interactions between the emitted particles. It has been predicted that correlations due to the strong final-state interactions in a system where a narrow resonance is present will be sensitive, in the region of the resonance, to the source size and momentum-space correlations. Such a measurement can provide complementary information to the measurements at very low relative momenta. This paper presents the preliminary results of a STAR analysis of unlike-sign kaon femtoscopic correlations in Au+Au collisions at root s(NN)=200 GeV, including the region of phi(1020) resonance. The experimental results are compared to a theoretical prediction that includes the treatment of resonance formation due to the final-state interactions.