Baryon-baryon interactions with strangeness studied from hypernuclei

Structure of hypernuclei provides valuable information on baryon-baryon interactions. We have studied the ΛN spin-dependent interactions from precise level structure of p-shell Λ hypernuclei by means of a recently-developed technique of hypernuclear γ-ray spectroscopy with the germanium detector array, Hyperball. The strengths of the spin-spin, spin-orbit, and tensor interactions have been experimentally determined from LiΛ7, BeΛ9, and OΛ16 hypernuclear level energies. Consistency check of the strength parameters has been also made with more p-shell hypernuclear data. Experimental results on double Λ hypernuclei and Σ hypernuclei have also provided information on ΛΛ and ΣN interactions.