final-state interaction in the reactions and

Johann Haidenbauer; Ulf-G. Meißner

doi:10.1140/epja/s10050-024-01345-z

2024 Impact factor 2.8

Hadrons and Nuclei

Open Access

Eur. Phys. J. A (2024) 60: 119
https://doi.org/10.1140/epja/s10050-024-01345-z

Regular Article –Theoretical Physics

$p \bar{Λ}$ $p\bar{\varLambda }$ final-state interaction in the reactions $e^{+} e^{-} \to K^{-} p \bar{Λ}$ $e^+e^- \rightarrow K^- p \bar{\varLambda }$ and $J / ψ \to K^{-} p \bar{Λ}$ $J/\psi \rightarrow K^- p \bar{\varLambda }$

Johann Haidenbauer¹^a and Ulf-G. Meißner¹^,2

¹ Institute for Advanced Simulation (IAS-4), Forschungszentrum Jülich, D-52428, Jülich, Germany
² Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, 53115, Bonn, Germany

^a j.haidenbauer@fz-juelich.de

Received: 4 April 2024
Accepted: 17 May 2024
Published online: 31 May 2024

Abstract

Near-threshold $p \bar{Λ}$ $p\bar{\Lambda }$ mass spectra for the reactions $e^{+} e^{-} \to K^{-} p \bar{Λ}$ $e^+e^- \rightarrow K^- p\bar{\Lambda }$ and $J / ψ \to K^{-} p \bar{Λ}$ $J/\psi \rightarrow K^- p\bar{\Lambda }$ are investigated with an emphasis on the role played by the interaction in the $p \bar{Λ}$ $p\bar{\Lambda }$ system. As guideline for the $p \bar{Λ}$ $p\bar{\Lambda }$ interaction a variety of $Λ \bar{Λ}$ $\Lambda \bar{\Lambda }$ potential models is considered that have been established in the analysis of data on $p \bar{p} \to Λ \bar{Λ}$ $p{\bar{p}}\rightarrow \Lambda \bar{\Lambda }$ in the past. Arguments why the properties of the $p \bar{Λ}$ $p\bar{\Lambda }$ and $Λ \bar{Λ}$ $\Lambda \bar{\Lambda }$ interactions can be expected to be very similar are provided. It is shown that the near-threshold enhancement in the invariant mass observed for the $e^{+} e^{-}$ $$e^+e^-$$ reaction can be reproduced quantitatively by the assumed $p \bar{Λ}$ $p\bar{\Lambda }$ final-state interaction in the partial wave suggested by an amplitude analysis of the experiment. The effect of the $p \bar{Λ}$ $p\bar{\Lambda }$ final-state interaction in other decays is explored, including the recently measured reactions $B^{-} \to J / ψ \bar{p} Λ$ $B^- \rightarrow J/\psi \, {\bar{p}} \Lambda$ and $B^{+} \to J / ψ p \bar{Λ}$ $B^+ \rightarrow J/\psi \, p \bar{\Lambda }$ . It is found that the final-state interaction improves the description of the measured invariant mass near threshold in most cases.

© The Author(s) 2024

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