Orateur
Description
The first measurements of femtoscopic correlations with the particle-pair combinations
$\pi^{\pm}$ $K^0_S$ in pp collisions at $\sqrt{s}$ = 13 TeV are reported by ALICE. It is
shown that it is possible to study the elusive $K^*_0(700)$ particle that has been
considered a tetraquark candidate for over forty years. Boson source parameters and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state
interaction is modeled through a resonant scattering amplitude, defined in terms of a mass
and a coupling parameter, decaying into a $\pi^{\pm}$ $K^0_S$ pair. The extracted mass
and Breit-Wigner width, derived from the coupling parameter of the final-state interaction
are found to be consistent with previous measurements of the $K^*_0(700)$. The small
value and increasing behavior of the correlation strength with increasing source size
support the hypothesis that the $K^*_0(700)$ is a tetraquark state. This latter trend is also
confirmed via a simple geometric model that assumes a tetraquark structure of the
$K^*_0(700)$ resonance.
