$Λ^+_c$- and $Λ_b$-hypernuclei

Abstract

$Λ^+_c$- and $Λ_b$-hypernuclei are studied in the quark-meson coupling (QMC) model. Comparisons are made with the results for $Λ$-hypernuclei studied in the same model previously. Although the scalar and vector potentials felt by the $Λ$, $Λ_c^+$ and $Λ_b$ in the corresponding hypernuclei multiplet which has the same baryon numbers are quite similar, the wave functions obtained, e.g., for $1s_{1/2}$ state, are very different. The $Λ^+_c$ baryon density distribution in $^{209}_{Λ^+_c}$Pb is much more pushed away from the center than that for the $Λ$ in $^{209}_Λ$Pb due to the Coulomb force. On the contrary, the $Λ_b$ baryon density distributions in $Λ_b$-hypernuclei are much larger near the origin than those for the $Λ$ in the corresponding $Λ$-hypernuclei due to its heavy mass. It is also found that level spacing for the $Λ_b$ single-particle energies is much smaller than that for the $Λ$ and $Λ^+_c$.

Latex, 14 pages, 4 figures, text was extended, version to appear in Phys. Rev. C