Summary

High-resolution (e,e'K$^+$) spectroscopy for the four targets, $^{12}$C, $^{28}$Si, $^{51}$V and $^{89}$Y has been proposed. By the proposed spectroscopy, we plan to reveal 1) Single-particle nature of a $\Lambda$ hyperon by deriving single particle binding energies and widths and/or splitting of the single-particle states in wide mass range; 2) Splitting of higher-$l$ single particle states in view of $\Lambda$N $ls$ interaction and also structural origin; and 3) Characteristic structure of $^{12}_{\Lambda }$B, $^{28}_{\Lambda }$Al, $^{51}_{\Lambda }$Ti and $^{89}_{\Lambda}$Sr. Puzzling core excited states in $^{12}_{\Lambda }$B( $^{12}_{\Lambda }$C) will be intensively studied with high quality spectrum.

An exploratory spectrum will be also taken for the $^{89}$Y target, in order to examine the possibility to extend hypernuclear spectroscopy to the heavier targets.

The present proposal assumes the high resolution kaon spectrometer (HKS) under construction by the Tohoku group with the Monbusho budget. The proposal is fully based on the success of the E89-009 experiment carried out in the spring of 2000. Once the proposed experiment is successfully carried out, we envision that the hypernuclear physics program by the (e,e'K$^+$) reaction will be fully explored as 1) $\Lambda$ hypernuclear spectroscopy for targets as heavy as Pb; 2) Intensive high quality spectroscopy of light $\Lambda$ hypernuclei; and also 3) Open a path way toward weak decay experiments taking advantage of high-quality high-power electron beam at Jefferson Laboratory.