A series of hypernuclear γ-ray spectroscopy experiments using a germanium detector array, Hyperball, have accumulated precise data on various p-shell Λ hypernuclei. Recently, 12ΛC and 11ΛB were studied at KEK using the (π+, K+ γ) reaction, and a transition from a directly-populated spin-flip state, 16ΛO(2-), was observed in BNL E930 data. It is discussed whether the spin-dependent ΛN interaction parameters determined from previous experiments can consistently explain other γ spectroscopy data. At the J-PARC facility, further hypernuclear γ-ray spectroscopy experiments are planned, particularly to measure the g factor of a Λ in a nucleus from a spin-flip B (M 1) value and to investigate the ΛN interaction more in detail.
- Gamma transitions and level energies
- Hyperon-nucleon interactions