Constraining the low-energy S=−2 meson-baryon interaction with two-particle correlations

In this paper we present a novel method to extract information on hadron-hadron interactions using for the first time femtoscopic data to constrain the low-energy constants of a QCD effective Lagrangian. This method offers a new way to investigate the nonperturbative regime of QCD in sectors where scattering experiments are not feasible, such as the multistrange and charm ones. As an example of its application, we use the very precise <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mi mathvariant="normal">K</a:mi></a:mrow><a:mrow><a:mo>−</a:mo></a:mrow></a:msup><a:mi mathvariant="normal">Λ</a:mi></a:mrow></a:math> correlation function data, recently measured in <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>p</e:mi><e:mi>p</e:mi></e:math> collisions at LHC, to constrain the strangeness <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mi>S</g:mi><g:mo>=</g:mo><g:mo>−</g:mo><g:mn>2</g:mn></g:math> meson-baryon interaction. The model obtained delivers new insights on the molecular nature of the <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mi mathvariant="normal">Ξ</i:mi><i:mrow><i:mo stretchy="false">(</i:mo><i:mn>1620</i:mn><i:mo stretchy="false">)</i:mo></i:mrow></i:math> and <n:math xmlns:n="http://www.w3.org/1998/Math/MathML" display="inline"><n:mi mathvariant="normal">Ξ</n:mi><n:mrow><n:mo stretchy="false">(</n:mo><n:mn>1690</n:mn><n:mo stretchy="false">)</n:mo></n:mrow></n:math> states.