Investigation of K+K- interactions via femtoscopy in Pb-Pb collisions at sNN =2.76 TeV at the CERN Large Hadron Collider

Abstract

Femtoscopic correlations of nonidentical charged kaons ( K + K − ) are studied in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon collision √ s N N = 2.76 TeV by ALICE at the CERN Large Hadron Collider. One-dimensional K + K − correlation functions are analyzed in three centrality classes and eight intervals of particle-pair transverse momentum. The Lednický and Luboshitz interaction model used in the K + K − analysis includes the final-state Coulomb interactions between kaons and the final-state interaction through a 0 ( 980 ) and f 0 ( 980 ) resonances. The mass of f 0 ( 980 ) and coupling were extracted from the fit to K + K − correlation functions using the femtoscopic technique. The measured mass and width of the f 0 ( 980 ) resonance are consistent with other published measurements. The height of the ϕ ( 1020 ) meson peak present in the K + K − correlation function rapidly decreases with increasing source radius, qualitatively in agreement with an inverse volume dependence. A phenomenological fit to this trend suggests that the ϕ ( 1020 ) meson yield is dominated by particles produced directly from the hadronization of the system. The small fraction subsequently produced by final-state interactions could not be precisely quantified with data presented in this paper and will be assessed in future work.