High resolution hypernuclear spectroscopy at Jefferson Lab Hall A

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 1p-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-12(Lambda) spectrum. For O-16 a high-quality N-16(Lambda) spectrum was produced for the first time with sub-MeV energy resolution. A very precise A binding energy value for N-16(Lambda), calibrated against the elementary (e, e'K+) reaction on hydrogen, has also been obtained. Preliminary data on the Li-9(Lambda) spectrum shows some disagreement in strength for the second and third doublet with respect to the theory. (c) 2013 Elsevier B.V. All rights reserved.