Spectroscopic study of Λ hypernuclei by the (e, e′K~+) reaction

摘要

The hypernuclear spectroscopy via the (e, e′K~+) reaction has been carried out for the first time. The high quality electron beam at Jefferson Lab made it possible to measure Λ hypernuclear spectra with energy resolution better than 1 MeV (FWHM). The present experiment was designed to make full use of virtual photon flux which peaks at very forward angles by detecting scattered electrons at 0 degrees. The ~(12)_ΛB mass spectrum was measured in the ~(12)C (e,e′K~+) ~(12)_ΛB reaction with 0.9 MeV (FWHM) energy resolution. The binding energy and cross section of the ~(12)_ΛB ground state doublet were obtained and discussed in this article. The present study proved the effectiveness of the (e,e′K~+) reaction in the future Λ hypernuclear spectroscopy.