Femtoscopic study of the S = −1 meson-baryon interaction: p-wave effects in K−p, K+Ξ− and π−Λ systems

Abstract

This study investigates the effects of higher partial waves of the strangeness S = −1 meson-baryon interaction on the femtoscopic correlation function (CF) of K−p, K+Ξ−, and π−Λ systems. The meson-baryon interaction up to p-waves (L = 1) is built following the Chiral Perturbation Theory scheme, combined with a non-perturbative approach via the Bethe-Salpeter equation. The s-wave term determines the JP = 1/2− interaction, whereas the p-wave terms define the JP = 1/2+ and JP = 3/2+ ones. The results show that the CF of K−p pairs remains unchanged under the addition of the p-waves, staying dominated by the Λ(1405) resonance. Similarly, the K+Ξ− CF is hardly affected by the p-waves and retains a shape characteristic of the presence of the subthreshold s-wave Λ(1670) resonance. In contrast, the CF in the π−Λ channel shows a clear dip associated to the JP = 3/2+ term of the p-wave interaction, associated to the clear effects of the Σ∗ resonance