The Λ separation energies in the mirror hypernuclei Λ4H-Λ4He exhibit large charge symmetry breaking (CSB). Analyzing this CSB within pionless effective field theory while using partially conserved baryon-baryon SU(3) flavor symmetry, we deduce a Λ-ς0 induced in-medium admixture amplitude AI=1≈1.5% in the dominantly isospin I=0Λ hyperon. Our results confirm the free-space value AI=1(0) inferred directly within the SU(3) baryon octet by Dalitz and von Hippel in 1964 and reaffirmed in a recent QCD+QED lattice calculation. Furthermore, exploring the consequences of SU(3) flavor symmetry on the Λ-nucleon interaction, we find that CSB is expected to impact the S=1 and S=0 spin channels in opposite directions, with the latter dominating by an order of magnitude. These observations explain a recent deduction of Λ-nucleon CSB strengths.
Bibliographical noteFunding Information:
A.G. would like to thank Johann Haidenbauer and Wolfram Weise for instructive discussions on EFT approaches to strange few-body systems. The work of M.S. and N.B. was supported by the Pazy Foundation and by the Israel Science Foundation Grant No. 1086/21. Furthermore, the work of A.G. and N.B. is part of a project funded by the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 824093.
© 2022 American Physical Society.