Constraining the {overline{textrm{K}}}{textrm{N}} coupled channel dynamics using femtoscopic correlations at the LHC

Abstract

The interaction of textrm{K}^{-}with protons is characterised by the presence of several coupled channels, systems like {overline{textrm{K}}}^0n and uppi Sigma with a similar mass and the same quantum numbers as the textrm{K}^{-}p state. The strengths of these couplings to the textrm{K}^{-}p system are of crucial importance for the understanding of the nature of the Lambda (1405) resonance and of the attractive textrm{K}^{-}p strong interaction. In this article, we present measurements of the textrm{K}^{-}p correlation functions in relative momentum space obtained in pp collisions at sqrt{s}~=~13 Te, in p–Pb collisions at sqrt{s_{textrm{NN}}}~=~5.02 Te, and (semi)peripheral Pb–Pb collisions at sqrt{s_{textrm{NN}}}~=~5.02 Te. The emitting source size, composed of a core radius anchored to the textrm{K}^{+}p correlation and of a resonance halo specific to each particle pair, varies between 1 and 2 fm in these collision systems. The strength and the effects of the {overline{textrm{K}}}^0n and uppi Sigma inelastic channels on the measured textrm{K}^{-}p correlation function are investigated in the different colliding systems by comparing the data with state-of-the-art models of chiral potentials. A novel approach to determine the conversion weights omega , necessary to quantify the amount of produced inelastic channels in the correlation function, is presented. In this method, particle yields are estimated from thermal model predictions, and their kinematic distribution from blast-wave fits to measured data. The comparison of chiral potentials to the measured textrm{K}^{-}p interaction indicates that, while the uppi Sigma –textrm{K}^{-}p dynamics is well reproduced by the model, the coupling to the {overline{textrm{K}}}^0n channel in the model is currently underestimated.