High resolution hypernuclear spectroscopy at Jefferson Lab Hall A

Abstract The characteristics of the Jefferson Lab electron beam, together with those of the experimental equipment, offer a unique opportunity to study hypernuclear spectroscopy via electromagnetic induced ( e , e ′ K + ) reactions. Experiment 94-107 started a systematic study on 1 p -shell targets, C 12 , Be 9 and O 16 . For C 12 for the first time measurable strength in the core-excited part of the spectrum between the ground state and the p state was shown in the B Λ 12 spectrum. For O 16 a high-quality N Λ 16 spectrum was produced for the first time with sub-MeV energy resolution. A very precise Λ binding energy value for N Λ 16 , calibrated against the elementary ( e , e ′ K + ) reaction on hydrogen, has also been obtained. Preliminary data on the Li Λ 9 spectrum shows some disagreement in strength for the second and third doublet with respect to the theory.