Study of the Λ–Λ interaction with femtoscopy correlations in pp and p–Pb collisions at the LHC

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Abstract

This work presents new constraints on the existence and the binding energy of a possible Λ–Λ bound state, the H-dibaryon, derived from Λ–Λ femtoscopic measurements by the ALICE collaboration. The results are obtained from a new measurement using the femtoscopy technique in (Figure presented.) collisions at s=13 TeV and p–Pb collisions at sNN=5.02 TeV, combined with previously published results from (Figure presented.) collisions at s=7 TeV. The Λ–Λ scattering parameter space, spanned by the inverse scattering length f0 −1 and the effective range d0, is constrained by comparing the measured Λ–Λ correlation function with calculations obtained within the Lednický model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the Λ–Λ interaction. The region in the (f0 −1,d0) plane which would accommodate a Λ–Λ bound state is substantially restricted compared to previous studies. The binding energy of the possible Λ–Λ bound state is estimated within an effective-range expansion approach and is found to be BΛΛ=3.2−2.4 +1.6(stat)−1.0 +1.8(syst) MeV. © 2019 The Author(s)

Details

Authors
Organisations
External organisations
  • University of Copenhagen
  • Variable Energy Cyclotron Centre
  • University of Brescia
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics
Original languageEnglish
Article number134822
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume797
Publication statusPublished - 2019
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

Export Date: 9 September 2019