We present the first ever measurements of femtoscopic correlations between the Kos and K± particles. The analysis was performed on the data from Pb–Pb collisions at √sNN=2.76 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the a0(980) resonance. The extracted kaon source radius and correlation strength parameters for K os K- are found to be equal within the experimental uncertainties to those for K os K+ . Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the ao resonance are tested. Our results are also compatible with the interpretation of the ao having a tetraquark structure instead of that of a diquark
