Like-sign pion femtoscopy in p+p collisions at s = 3.46 GeV

In this paper, we present the current results from the femtoscopic analysis of like-sign pion pairs extracted from proton-proton collisions at [Formula: see text] GeV measured with HADES. While femtoscopy of pions is well known in the case of heavy-ion collisions and/or high energies, the Koonin-Pratt formalism that describes femtoscopy might not hold for low-energy elementary collisions. With that in mind, we show that, when accounting for detector effects using the double-ratio method and dedicated SMASH events propagated through the simulated detector with Geant 3, it is possible to extract the femtoscopic parameters from such collisions. The obtained parameters show a small source size of around 1.5 fm with a very small correlation strength parameter of around 0.15.