The λ13C hypernucleus was studied by measuring γ rays in coincidence with the 13C(K-, π-) reaction, γ rays from the 1/2- and 3/2- states, which are the partners of the spin-orbit doublet states with a predominant configuration of [12Cg.s.(0+)⊗pΛ], to the ground state were measured. The splitting of the states was found to be ΔE(1/2--3/2-) = + 152±54(stat)±36(syst) keV. This value is 20-30 times smaller than that of single particle states in nuclei around this mass region. The jΛ = ℓΛ - 1/2[(p1/2)Λ] state appeared higher in energy, as in normal nuclei. The value gives new insight into the YN interaction. The excitation energies of the 1/2- and 3/2- states were obtained as 10.982±0.031(stat)±0.056(syst) and 10.830±0.031(stat)±0.056(syst) MeV, respectively. We also observed γ rays from the 3/2+ state, which has a [12C(2+)⊗ sΛ] configuration, to the ground state in Λ13C. The excitation energy of the 3/2+ state was obtained as 4.880 ± 0.010(stat) ±0.017(syst) MeV. Nuclear γ rays with energies of 4.438 and 15.100 MeV had similar yields, which suggests that a quasifree knockout of a Λ particle is dominant in highly excited regions.
|Number of pages||9|
|Journal||Physical Review C - Nuclear Physics|
|Publication status||Published - 2002 Mar|
ASJC Scopus subject areas
- Nuclear and High Energy Physics