Investigating the role of strangeness in baryon-antibaryon annihilation at the LHC

Annihilation dynamics plays a fundamental role in the baryon-antibaryon interaction (B-(B) over bar) at low-energy and its strength and range are crucial in the assessment of possible baryonic bound states. Experimental data on annihilation cross sections are available for the p-(p) over bar system but not in the low relative momentum region. Data regarding the B-(B) over bar interaction with strange degrees of freedom are extremely scarce, hence the modeling of the annihilation contributions is mainly based on nucleon-antinucleon (N-(N) over bar) results, when available. In this letter we present a measurement of the p-(p) over bar, p-(Lambda) over bar circle plus(p) over bar-Lambda and Lambda-(Lambda) over bar interaction using correlation functions in the relative momentum space in high-multiplicity triggered pp collisions at root s = 13 TeV recorded by ALICE at the LHC. In the p-(p) over bar system the couplings to the mesonic channels in different partial waves are extracted by adopting a coupled-channel approach with recent chi EFT potentials. The inclusion of these inelastic channels provides good agreement with the data, showing a significant presence of the annihilation term down to zero momentum. Predictions obtained using the Lednicky-Lyuboshits formula and scattering parameters obtained from heavy-ion collisions, hence mainly sensitive to elastic processes, are compared with the experimental p-(Lambda) over bar circle plus(p) over bar-Lambda and Lambda-(Lambda) over bar correlations. The model describes the Lambda-(Lambda) over bar data and underestimates the p-(Lambda) over bar circle plus(p) over bar-Lambda data in the region of momenta below 200 MeV/c. The observed deviation indicates a different contribution of annihilation channels to the two systems containing strange hadrons. (C) 2022 European Organization for Nuclear Research. Published by Elsevier B.V.