Formation of Hyper Hydrogen isotopes in light p-shell nuclei

Abstract

Recent experiment by A1 Collaboration at Mainz, namely identification of _Λ⁴H hyperfragment from primary _Λ⁹Li hypernucleus produced in reaction (e, e′K⁺), stirred renewed interest in baryonic decay of hypernuclei. The important role of s⁻¹s_Λ excitation in p-shell hypernuclei as well as the existence of selection rules connected with [f] (Young diagram) was noted earlier within Translational Invariant Shell Model (TISM). The particular conditions of the present experiment (reaction is not selective and produces highly excited states) dictate extension of the simplest TISM: expansion of the harmonic oscillator basis space and compression of multiplets (to only (λμ) for L and [f] for S, T). Such modified TISM explains abundance production of _Λ⁴H hyperfragment and predicts production of another Hyper Hydrogen _Λ⁶H.