Speaker
Description
The interaction between $\Lambda$ baryons and kaons/antikaons is a crucial ingredient for low energies effective models aiming at describing the strangeness $S=0$ ($\Lambda$K) and $S=-2$ ($\Lambda$$\mathrm{\bar{K}}$) sector of the meson-baryon interaction.
Of particular interest is the $\Lambda$$\mathrm{\bar{K}}$ interaction, where the presence of the \XRes close to the threshold should play a significant role. The $\pi\Xi$ decay channel of the $\Xi(1620)$ resonance has been recently observed by the Belle collaboration, providing the first experimental values for its mass and width. However, no measurements are available for the $\Lambda$$\mathrm{\bar{K}}$ channel. Delivering high-precision data on the $\Lambda$$\mathrm{\bar{K}}$ system can help to shed light into the nature of the $\Xi(1620)$ state and its formation. Experimental data on $\Lambda$$\mathrm{\bar{K}}$, and as well on $\Lambda$K, are currently rather scarce, leading to large uncertainties and tensions between the available theoretical predictions. Recently, measurements of two-particle correlations in small colliding systems such as pp collisions at the LHC provided a significant improvement in the knowledge of several hadron-hadron interactions, in particular when strange baryons and mesons are involved.
In this talk, we present $\Lambda$K$^+$ and $\Lambda$K$^-$ femtoscopic correlations measured by ALICE in pp collisions at $\sqrt{s}=13$ TeV, obtained with a high-multiplicity trigger. The measurements indicate a repulsive interaction for $\Lambda$K$^+$ pairs and an attractive interaction for $\Lambda$K$^-$. In particular, we will show the first experimental evidence of the $\Xi(1620)$ decaying into $\Lambda$K$^-$ pairs and discuss the effect of the $\Xi(1620)$ state on the $\Lambda$$\mathrm{\bar{K}}$ interaction.
| Collaboration | ALICE |
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