# Measurement of strange baryon-antibaryon interactions with femtoscopic correlations

## TL;DR

This study measures baryon-antibaryon interactions in heavy-ion collisions using femtoscopic correlations, revealing strong, annihilative interactions and providing scattering parameters for various pairs, including first-time measurements for some.

## Contribution

It presents the first measurement of scattering parameters for $
m ar{ ext{Lambda}} ext{Lambda}$ pairs and provides effective averaged parameters for heavier baryon-antibaryon pairs.

## Key findings

- Strong baryon-antibaryon interactions observed.
- Non-zero imaginary part of scattering length indicates annihilation.
- Results suggest potential for baryon-antibaryon bound state searches.

## Abstract

Two-particle correlation functions were measured for $\rm p\overline{p}$, $\rm p\overline{\Lambda}$, $\rm \overline{p}\Lambda$, and $\Lambda\overline{\Lambda}$ pairs in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV and $\sqrt{s_{\rm NN}}=5.02$ TeV recorded by the ALICE detector. From a simultaneous fit to all obtained correlation functions, real and imaginary components of the scattering lengths, as well as the effective ranges, were extracted for combined $\rm p\overline{\Lambda}$ and $\rm \overline{p}\Lambda$ pairs and, for the first time, for $\Lambda\overline{\Lambda}$ pairs. Effective averaged scattering parameters for heavier baryon-antibaryon pairs, not measured directly, are also provided. The results reveal similarly strong interaction between measured baryon-antibaryon pairs, suggesting that they all annihilate in the same manner at the same pair relative momentum $k^{*}$. Moreover, the reported significant non-zero imaginary part and negative real part of the scattering length provide motivation for future baryon-antibaryon bound state searches.