Measurement of strange baryon–antibaryon interactions with femtoscopic correlations

Summary, in English

Two-particle correlation functions were measured for pp‾, pΛ‾, p‾Λ, and ΛΛ‾ pairs in Pb–Pb collisions at sNN=2.76 TeV and sNN=5.02 TeV recorded by the ALICE detector. From a simultaneous fit to all obtained correlation functions, real and imaginary components of the scattering lengths, as well as the effective ranges, were extracted for combined pΛ‾ and p‾Λ pairs and, for the first time, for ΛΛ‾ pairs. Effective averaged scattering parameters for heavier baryon–antibaryon pairs, not measured directly, are also provided. The results reveal similarly strong interaction between measured baryon–antibaryon pairs, suggesting that they all annihilate in the same manner at the same pair relative momentum k⁎. Moreover, the reported significant non-zero imaginary part and negative real part of the scattering length provide motivation for future baryon–antibaryon bound state searches.

• Author: S Acharya; Jonatan Adolfsson; Peter Christiansen; Martin Ljunggren; Adrian Nassirpour; Anders Oskarsson; Tuva Richert; Omar Vazquez Rueda; David Silvermyr; Evert Stenlund; N Zurlo
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2020-03-10
• Language: English
• Publication/Series: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 802
• Links: http://dx.doi.org/10.1016/j.physletb.2020.135223
• Document type: Journal article
• Publisher: Elsevier
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0370-2693