Experimental goals

Based on the experience obtained in the E89-009 experiment, we plan to take into account the following two key points for the proposed experimental configuration.

• A new high resolution kaon spectrometer (HKS) which is under construction will have 20 msr solid angle with the splitter and simultaneously achieve around a few 100 keV resolution.
• A new experimental configuration will maximize hypernuclear production rates by avoiding the 0-degree bremsstrahlung electrons but still measure scattered electrons at a sufficiently forward angle. ``Tilt method'' in which the Enge electron spectrometer is tilted by 2-3 degrees vertically will allow us to accept a beam current as high as a few tens $\mu$A.

It is emphasized that hypernuclear yield/nb/sr is approximately inversely proportional to hypernuclear mass number with the proposed ``Tilt method'', while the beam intensity was limited by brems electron rates since it is governed by inverse of Z$^{2+\delta}$ when the 0 degree tagging method is employed. Therefore, the ``Tilt method'' is much advantageous for the spectroscopy of heavier $\Lambda$ hypernuclei than the ``0 degree tagging method''. The new ``Tilt method'' inherits advantageous aspects of the 0-degree tagging method, but allows us to accept much higher beam currents because the high rate brems electrons are not allowed to enter the Enge spectrometer.