Jun 1 – 2, 2023
Europe/Berlin timezone

Accessing the strong interaction between Λ baryons and strange hadrons with femtoscopy at LHC

Jun 2, 2023, 10:00 AM



Valentina Mantovani Sarti (TUM)


Traditional experimental approaches, such as scattering and hypernuclei measurements, are insufficient to provide stringent constraints to
the theoretical modeling of the interaction between strange hadrons and hence questions on the existence and nature of predicted exotic bound states or resonances are still open.
In the baryon-baryon interaction, this is indeed the case for the H-dibaryon, predicted to be a bound state of two Λ baryons, but currently its experimental observation is not confirmed.
Of particular interest in the meson-baryon sector is the Λ-antiK interaction, where the presence of the Ξ(1620) close to the threshold should play a significant role in the underlying interaction. The πΞ decay channel of the Ξ(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 Λ-antiK channel. Delivering high-precision data on the Λ-antiK system can help to shed light into the nature of the Ξ(1620) state and its formation. Experimental data on Λ-antiK 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 and p-Pb 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 the results on the Λ-Λ and Λ-K- femtoscopic correlations measured by ALICE in pp collisions and p-Pb collisions. The measurements provides more precise upper limits on the H-dibaryon binding energy and show an attractive interaction for Λ-K-. In particular, we will show the first experimental evidence of the Ξ(1620) decaying into Λ-K- pairs. We will discuss the extracted properties of the Ξ(1620) state based on recent comparison of these data with state-of-the-art chiral calculations for the Λ-antiK interaction.

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