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Sumit Basu (Lund University)

Sumit Basu

Postdoctoral Researcher

Sumit Basu (Lund University)

Exploring the NΛ–NΣ coupled system with high precision correlation techniques at the LHC

Author

  • S. Acharya
  • J. Adolfsson
  • S. Basu
  • P. Christiansen
  • O. Matonoha
  • A.F. Nassirpour
  • A. Ohlson
  • A. Oskarsson
  • T. Richert
  • O.V. Rueda
  • D. Silvermyr
  • N. Zurlo
Show all

Summary, in English

The interaction of Λ and Σ hyperons (Y) with nucleons (N) is strongly influenced by the coupled-channel dynamics. Due to the small mass difference of the NΛ and NΣ systems, the sizable coupling strength of the NΣ↔NΛ processes constitutes a crucial element in the determination of the NΛ interaction. In this letter we present the most precise measurements on the interaction of pΛ pairs, from zero relative momentum up to the opening of the NΣ channel. The correlation function in the relative momentum space for pΛ⊕p‾Λ‾ pairs measured in high-multiplicity triggered pp collisions at s=13 TeV at the LHC is reported. The opening of the inelastic NΣ channels is visible in the extracted correlation function as a cusp-like structure occurring at relative momentum k⁎=289MeV/c. This represents the first direct experimental observation of the NΣ↔NΛ coupled channel in the pΛ system. The correlation function is compared with recent chiral effective field theory calculations, based on different strengths of the NΣ↔NΛ transition potential. A weaker coupling, as possibly supported by the present measurement, would require a more repulsive three-body NNΛ interaction for a proper description of the Λ in-medium properties, which has implications on the nuclear equation of state and for the presence of hyperons inside neutron stars. © 2022 European Organization for Nuclear Research, ALICE

Department/s

  • Particle and nuclear physics
  • eSSENCE: The e-Science Collaboration

Publishing year

2022

Language

English

Publication/Series

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

Volume

833

Document type

Journal article

Publisher

Elsevier

Topic

  • Subatomic Physics

Status

Published

ISBN/ISSN/Other

  • ISSN: 0370-2693