The $\bf{\Lambda p}$ interaction studied via femtoscopy in p + Nb reactions at $\mathbf{\sqrt{s_{NN}}=3.18} ~\mathrm{\bf{GeV}}$

We report on the first measurement of pΛ and pp correlations via the femtoscopy method in p + Nb reactions at sNN=3.18GeV, studied with the High Acceptance Di-Electron Spectrometer (HADES). By comparing the experimental correlation function to model calculations, a source size for pp pairs of r0,pp=2.02±0.01(stat)−0.12+0.11(sys)fm and a slightly smaller value for pΛ pairs of r0,Λp=1.62±0.02(stat)−0.08+0.19(sys)fm are extracted. Using the geometrical extent of the particle-emitting region, determined experimentally with pp correlations as reference together with a source function from a transport model, it is possible to study different sets of scattering parameters. The pΛ correlation is proven to be sensitive to predicted scattering length values from chiral effective field theory. We demonstrate that the femtoscopy technique can be used as a valid alternative to the analysis of scattering data to study the hyperon-nucleon interaction.