Speaker
Description
Femtoscopic correlations between K$^0_{\rm S}$ and K$^{\rm \pm}$ are studied for the first time. Unlike the case of identical-kaon pairs which have correlations from quantum statistics and, if charged, the Coulomb interaction, K$^0_{\rm S}$K$^{\rm \pm}$ correlations can only take place through a strong final-state interaction. Analyses were performed on data from Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV and pp collisions at $\sqrt{s}=7$ TeV measured by the ALICE experiment. The observed correlations are found to be consistent with final-state interactions proceeding via the a$_0$(980) resonance. The extracted radius and lambda parameters for K$^0_{\rm S}$K$^{\rm -}$ are found to be equal within the experimental uncertainties to those for K$^0_{\rm S}$K$^{\rm +}$ in each case. Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, constraints are placed on the a$_0$(980) mass and coupling parameters. In addition, the results from the present study are used to address the question of the quark composition of the a$_0$(980) resonance, and suggest that it is a tetraquark state.
| List of tracks | Resonance decays at low, intermediate and at RHIC and LHC |
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