Spectroscopy of A hypernuclei in the (e,e'K+) reaction at Jefferson Lab

The coincidence experiment E01-011 (HKS), conducted in Hall C at Jefferson Laboratory in fall 2005, represents a new generation of high resolution A hypernuclei spectroscopy experiments. It exploits the benefits of the associated electroproduction mechanism via the (e,e'K+) reaction. Compared with the widely studied meson-induced reactions, the higher quality quasi-continuous electron beam produces the potential for high resolution energy spectra. Further, it provides information complementary to meson-induced reactions: light neutron-rich and mirror hypernuclei, enhanced population of states accessible by spin-flip channels. The newly introduced tilt method of the electron spectrometer (ENGE) greatly reduced the rate of the background electrons due to Bremsstrahlung and M0ller scattering. A brand new high resolution kaon spectrometer (HKS) together with a sophisticated detector package yielded excellent PID and momentum resolution. This resulted in quality missing mass spectra with energy resolution of approximately 400-500 keV (FWHM), an unprecedented value in hypernuclear reaction spectroscopy. The experiment measured the spectra of exotic neutron rich and mirror A hypernuclei( lambda )(7)He, ( Lambda )(12)B, ( lambda )(28)Al with high statistics.