The B factory, the Superconducting Super Collider, and an e+e- linear collider: How they stand against each other

Many high energy physicists in Japan will be participating in Superconducting Super Collider (SSC) experiments. KEK is planning to build a B factory. Japan Linear Collider (JLC) --- an e+e- linear collider with √s = (.5 ∼ 1.5) TeV --- is being considered as the future project at KEK. I have been asked to discuss the physics compatibilities and the relative merits of these three projects. From a physics point of view, nobody can argue against building an accelerator. Looking back at the past 40 years, we note that physics discoveries from new accelerators often far exceeded our original expectations. In order to make accelerators cost effective, their parameters must be tuned so that there is guaranteed physics. By guaranteed physics, I mean that a machine must be capable of observing new phenomena predicted by the most conventional standard model. Discoveries beyond such bottom line expectations should be treated as bonuses and should not be treated as major motivations for building a machine. I will first discuss the bottom line physics at SSC and at a B factory. I will then go on to discuss the compatibility of the two physics. Finally, I will discuss the physics at JLC, and its relationship with that at SSC and at a B factory