In a γ-ray spectroscopy experiment with the (K-,π-) reaction on a B10 target, we have observed the 7/2+→5/2+ spin-flip M1 transition in Λ7Li via γ-γ coincidence with the 5/2+→1/2+E2 transition. This is the first successful γ-γ coincidence measurement for hypernuclei. The measured M1γ-ray energy is 470.8±1.9(stat) ±0.6(syst) keV. The spacing of the 7/2+,5/2+ doublet is consistently explained using the strengths of the spin-spin, Λ-spin-orbit, and tensor interactions obtained from previous γ-spectroscopy experiments.
ASJC Scopus subject areas
- Nuclear and High Energy Physics