Journal ArticleSpectroscopy of A=9 hyperlithium by the (e,e′K+) reactionT. Gogami, C. ChennullMissing mass spectroscopy with the (e,e′K+) reaction was performed at Jefferson Laboratory's Hall C for the neutron rich Λ hypernucleus 9ΛLi. The ground state energy was obtained to be Bg.s.Λ=8.84±0.17stat.±0.15sys. MeV by using shell model calculations of a cross section ratio and an energy separation of the spin doublet states (3/2+1 and 5/2+1). In addition, peaks that are considered to be states of [8Li(3+)⊗sΛ=3/2+2,1/2+] and [8Li(1+)⊗sΛ=5/2+2,7/2+] were observed at EΛ(no. 2)=1.74±0.27stat.±0.11sys. MeV and EΛ(no. 3)=3.30±0.24stat.±0.11sys. MeV, respectively. The EΛ(no. 3) is larger than shell model predictions by a few hundred keV, and the difference would indicate that a 5He+t structure is more developed for the 3+ state than those for the 2+ and 1+ states in a core nucleus 8Li as a cluster model calculation suggests.2021-04-0110286115Physical reviewC103L041301-2469-9985https://doi.org/https://doi.org/10.1103/PhysRevC.103.L0413011812396National Science Foundation