Femtoscopic study of the $S=-1$ meson-baryon interaction: $K^-p$, $\pi^-\Lambda$ and $K^+\Xi^-$ correlations

TL;DR

This paper predicts meson-baryon correlation functions in the strangeness -1 sector using chiral scattering amplitudes, successfully reproduces existing data, and introduces new methods for calculating production weights relevant for femtoscopic measurements.

Contribution

It provides the first predictions for $ ext{π}^- ext{Λ}$ and $K^+ ext{Ξ}^-$ correlation functions and demonstrates the effectiveness of a chiral unitary approach in describing these interactions.

Findings

Successfully reproduces $K^-p$ correlation data.

Predicts measurable $ ext{π}^- ext{Λ}$ and $K^+ ext{Ξ}^-$ correlations.

Introduces two novel methods for computing production weights.

Abstract

We study the femtoscopic correlation functions of meson-baryon pairs in the strangeness $S=-1$ sector, employing unitarized s-wave scattering amplitudes derived from the chiral Lagrangian up to next-to-leading order. For the first time, we deliver predictions on the $\pi^-\Lambda$ and $K^+\Xi^-$ correlation functions which are feasible to be measured at the Large Hadron Collider. We also demonstrate that the employed model is perfectly capable of reproducing the $K^-p$ correlation function data measured by the same collaboration, without the need to modify the coupling strength to the $\bar{K}^0n$ channel, as has been recently suggested. In all cases, the effects of the source size on the correlation are tested. In addition, we present detailed analysis of the different coupled-channel contributions, together with the quantification of the relative relevance of the different terms in the interaction. These calculations require the knowledge of the so-called production weights, for which we present two novel methods to compute them.