SOME URGENT PROBLEMS IN MEDIUM AND HIGH-ENERGY NUCLEAR-PHYSICS

In this article, I wish to elucidate some problems which I believe are urgent in the area of medium and high energy nuclear physics. First, the adoption of the parton-model description of hadrons in high energy physics experiments has, over the last two decades, generated a conce ptual gap from the meson-baryon picture which is still used as the sta ndard language in medium or high energy nuclear physics. We suggest th at the key to bridge the gap is to try to understand, or to derive, th e various parton distributions at low or moderate Q(2) (say, up to a f ew GeV2) using the meson-baryon picture. As the second urgent problem in nuclear physics, I wish to echo the standard wisdom that strong int eraction physics, as based on quantum chromodynamics (QCD), must be tr eated in a quantitative manner for low- or medium-energy processes inv olving hadrons. Here we have chosen to follow the route of using QCD s um rules to offer some solutions, as an alternative to the commonly ac cepted approach based upon lattice simulations. Finally, I believe tha t it is highly essential, and of urgently important, to employ what we have learned in nuclear and particle physics to formulate, or to refo rmulate, certain problems in related areas such as astrophysics and co smology.