Measuring K0K± interactions using Pb–Pb collisions at √sNN = 2.76STeV

We present the first ever measurements of femtoscopic correlations between the K0 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 K0 K− are found to be equal within the experimental uncertainties to those for K0 K+ . Comparing the S S results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the a0 resonance are tested. Our results are also compatible with the interpretation of the a0 having a tetraquark structure instead of that of a diquark.