The $p\Lambda$ and $pp\Lambda$ correlation functions

TL;DR

This paper investigates $p\Lambda$ and $pp\Lambda$ scattering using femtoscopic correlation functions, providing insights into low-energy interactions of strange hadrons and analyzing the impact of different models and three-body forces.

Contribution

It introduces a detailed analysis of $p\\Lambda$ and $pp\\Lambda$ correlations using the hyperspherical adiabatic basis, connecting experimental data with theoretical models of hadron interactions.

Findings

Large low-energy peak in $pp\Lambda$ correlation function due to $J^\pi=1/2^+$ three-body state.

Different interaction models significantly affect the correlation functions.

Study constrains two- and three-body hyperon interactions.

Abstract

In this work we present the study of $p\Lambda$ and $pp\Lambda$ scattering processes using femtoscopic correlation functions. This observable has been recently used to access the low-energy interaction of hadrons emitted in the final state of high-energy collisions, delivering unprecedented precision information of the interaction among strange hadrons. The formalism for particle pairs is well established and it relates the measured correlation functions with the scattering wave function and the emission source. In the present work we analyze the $NN\Lambda$ scattering in free space and relate the corresponding wave function to the $pp\Lambda$ correlation measurement performed by the ALICE collaboration. The three-body problem is solved using the hyperspherical adiabatic basis. Regarding the $p\Lambda$ and $pp\Lambda$ interactions, different models are used and their impact on the correlation function is studied. The three body force considered in this work is anchored to describe the binding energy of the hypertriton and to give a good description of the two four-body hypernuclei. As a main result we have observed a huge, low-energy peak in the $pp\Lambda$ correlation function, mainly produced by the $J^\pi=1/2^+$ three-body state. The study of this peak from an experimental as well as a theoretical point of view will provide important constraints to the two- and three-body interactions.