Description of femtoscopic correlations with realistic pion-kaon interactions: the $\kappa/K^*_0(700)$ case

TL;DR

This paper models femtoscopic pion-kaon correlations in proton-proton collisions using realistic interactions derived from dispersive analysis, highlighting the impact of the $Kappa$ resonance and relativistic effects on correlation measurements.

Contribution

It introduces a model incorporating dispersive analysis-based $Kappa$ interactions and relativistic corrections to describe femtoscopic correlations involving pions and kaons.

Findings

Accurate description of $Kappa$ resonance in femtoscopic correlations.

Relativistic corrections significantly affect correlation functions.

The $Kappa$ resonance influences the source radius measurements.

Abstract

In this work, we show how $\pi^+ K_S$ femtoscopic correlations, recently reported by ALICE collaboration in $ pp $ collisions, can be well described taking into account relativistic corrections and using realistic $ \pi K $ interactions. These are obtained from a dispersive analysis of scattering data, which provides an accurate and model-independent description of the $ \kappa/K^*_0(700) $ resonance pole. The chiral symmetry suppression of the $ \pi K $ interactions at low energies and the non-ordinary features of the $ \kappa/K^*_0(700) $ seem to suggest that the $ \pi^+ K_S $ source radius might be surprisingly smaller than for other hadronic processes when using the standard and simple Lednicky-Lyuboshits factorization approximation.