Measuring K S 0 K ± interactions using Pb–Pb collisions at s NN = 2.76 TeV

摘要

We present the first ever measurements of femtoscopic correlations between the K S 0 and K ± particles. The analysis was performed on the data from Pb–Pb collisions at s NN = 2.76 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the a 0 ( 980 ) resonance. The extracted kaon source radius and correlation strength parameters for K S 0 K ? are found to be equal within the experimental uncertainties to those for K S 0 K + . Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the a 0 resonance are tested. Our results are also compatible with the interpretation of the a 0 having a tetraquark structure instead of that of a diquark.