`` $Λ- Σ$ conversion in $^4_Λ$He and $^4_Λ$H based on four-body calculation

Abstract

Precise four-body calculations for $^4_Λ$He and $^4_Λ$H have been performed in the framework of the variational method with Jacobian-coordinate Gaussian-basis functions. All the rearrangement channels of both $NNN Λ$ and $NNN Σ$ are explicitly taken into account for the first time with the use of realistic $NN$ and $YN$ interactions. The role of $Λ$-$Σ$ conversion and the amount of the virtual $Σ$-component in $^4_Λ$He and $^4_Λ$H are discussed.

14 pages, 8figures, submitted to Physical Review C